Re-add the CLI usage section.

README.md

@@ -23,6 +23,26 @@ cargo install steam-rss
 
 Precompiled `x86_64-unknown-linux-gnu` binaries are available on the [Releases page](https://git.bauke.xyz/Bauke/steam-rss/releases).
 
+## Usage
+
+```
+USAGE:
+    steam-rss [OPTIONS]
+
+OPTIONS:
+    -a, --appid <APPID>        A game's AppID, can be used multiple times
+    -h, --help                 Print help information
+        --opml                 Output the feeds as OPML
+    -t, --timeout <TIMEOUT>    The time in milliseconds to sleep between HTTP requests [default:
+                               250]
+        --url <URL>            A game's store URL, can be used multiple times
+        --user <USER>          A person's steamcommunity.com ID or full URL, can be used multiple
+                               times
+    -v, --verify               Verify potential feeds by downloading them and checking if they
+                               return XML
+    -V, --version              Print version information
+```
+
 ## Feedback
 
 Found a problem or want to request a new feature? Email [me@bauke.xyz](mailto:me@bauke.xyz) and I'll see what I can do for you.