README updates

README.md

@@ -34,7 +34,7 @@ deactivate
 cp config-example.yml config.yml
 ```
 
-Then edit `config.yml` in your text editor of choice to set up the software as you like it.
+Then edit `config.yml` in your text editor of choice to set up the software as you like it. Mostly, this will involve enabling or disabling the various providers of spot and alert data.
 
 `config.yml` has some entries for QRZ.com username & password, and Clublog API keys. If provided, these allow Spothole to retrieve more information about DX spots, such as the country their callsign corresponds to. The software will work just fine without them, but you may find a few country flags etc. are less accurate or missing.
 
@@ -57,6 +57,8 @@ If you see some errors on startup, check your configuration, e.g. in case you ha
 
 ### systemd configuration
 
+If you want Spothole to run automatically on startup on a Linux distribution that uses `systemd`, follow the instructions here. For distros that don't use `systemd`, or Windows/OSX/etc., you can find generic instructions for your OS online.
+
 Create a file at `/etc/systemd/system/spothole.service`. Give it the following content, adjusting for the user you want to run it as and the directory in which you have installed it:
 
 ```
@@ -87,7 +89,9 @@ Check the service has started up correctly with `sudo journalctl -u spothole -f`
 
 ### nginx Reverse Proxy configuration
 
-It's best not to serve Spothole directly on port 80, as that requires root privileges and prevents us using HTTPS, amongst other reasons. To set up nginx as a reverse proxy that sits in front of Spothole, first ensure it's installed e.g. `sudo apt install nginx`, and enabled e.g. `sudo systemd enable nginx`.
+Web servers generally serve their pages from port 80. However, it's best not to serve Spothole's web interface directly on port 80, as that requires root privileges on a Linux system. It also and prevents us using HTTPS to serve a secure site, since Spothole itself doesn't directly support acting as an HTTPS server. The normal solution to this is to use a "reverse proxy" setup, where a general web server handles HTTP and HTTP requests (to port 80 & 443 respectively), then passes on the request to the back-end application (in this case Spothole). nginx is a common choice for this general web server.
+
+To set up nginx as a reverse proxy that sits in front of Spothole, first ensure it's installed e.g. `sudo apt install nginx`, and enabled e.g. `sudo systemd enable nginx`.
 
 Create a file at `/etc/nginx/sites-available/` called `spothole`. Give it the following contents, replacing `spothole.app` with the domain name on which you want to run Spothole. If you changed the port on which Spothole runs, update that on the "proxy_pass" line too.
 
@@ -140,8 +144,8 @@ Once that's working, [install certbot](https://certbot.eff.org/instructions?ws=n
 Various approaches exist to writing your own client, but in general:
 
 * Refer to the API docs. These are built on an OpenAPI definition file (`/webassets/apidocs/openapi.yml`), which you can automatically use to generate a client skeleton using various software.
-* Call the main "spots" API to get the data you want. Apply filters if necessary.
-* Call the "options" API to get an idea of which bands, modes etc. the server knows about. You might want to do that first before calling the spots API.
+* Call the main "spots" or "alerts" API endpoints to get the data you want. Apply filters if necessary.
+* Call the "options" API to get an idea of which bands, modes etc. the server knows about. You might want to do that first before calling the spots/alerts APIs, to allow you to populate your filters correctly.
 * Refer to the provided HTML/JS interface for a reference
 * Let me know if you get stuck, I'm happy to help!
 
@@ -178,19 +182,21 @@ To navigate your way around the source code, this list may help.
 
 ### Extending the server
 
-Spothole is designed to be easily extensible. If you want to write your own provider, simply add a module to the `providers` package containing your class. (Currently, in order to be loaded correctly, the module (file) name should be the same as the class name, but lower case.)
+Spothole is designed to be easily extensible. If you want to write your own spot provider, for example, simply add a module to the `spotproviders` package containing your class. (Currently, in order to be loaded correctly, the module (file) name should be the same as the class name, but lower case.)
 
-Your class should extend "Provider"; if it operates by polling an HTTP Server on a timer, it can instead extend "HTTPProvider" where some of the work is done for you.
+Your class should extend "SpotProvider"; if it operates by polling an HTTP Server on a timer, it can instead extend "HTTPSpotProvider" where some of the work is done for you.
 
 The class will need to implement a constructor that takes in the `provider_config` and provides it to the superclass constructor, while also taking any other config parameters it needs.
 
-If you're extending the base `Provider` class, you will need to implement `start()` and `stop()` methods that start and stop a separate thread which handles the provider's processing needs. The thread should call `submit()` or `submit_batch()` when it has one or more spots to report.
+If you're extending the base `SpotProvider` class, you will need to implement `start()` and `stop()` methods that start and stop a separate thread which handles the provider's processing needs. The thread should call `submit()` or `submit_batch()` when it has one or more spots to report.
 
-If you're extending the `HTTPProvider` class, you will need to provide a URI to query and an interval to the superclass constructor. You'll then need to implement the `http_response_to_spots()` method which is called when new data is retrieved. Your implementation should then call `submit()` or `submit_batch()` when it has one or more spots to report.
+If you're extending the `HTTPSpotProvider` class, you will need to provide a URI to query and an interval to the superclass constructor. You'll then need to implement the `http_response_to_spots()` method which is called when new data is retrieved. Your implementation should then call `submit()` or `submit_batch()` when it has one or more spots to report.
 
 When constructing spots, use the comments in the Spot class and the existing implementations as an example. All parameters are optional, but you will at least want to provide a `time` (which must be timezone-aware) and a `dx_call`.
 
-Finally, simply add the appropriate config to the `providers` section of `config.yml`, and your provider should be instantiated on startup.
+Finally, simply add the appropriate config to the `spot_providers` section of `config.yml`, and your provider should be instantiated on startup.
+
+The same approach as above is also used for alert providers.
 
 ### Thanks