Update documentation cli.md (#1447)

Update with new parameters (from --help command)

docs/source/features/cli.md

@@ -17,12 +17,15 @@ Options:
                                  instances.
   -g, --no-debug-output          Disable just "debug" output.
   -n, --no-standard-output       Completely disable stdout/stderr outputs.
-  -w, --no-web-engine            Force usage of simpler text-based embedded web
-                                 browser.
+  -w, --lite                     Force lite variant of application.
   -t, --style <style-name>       Force some application style.
   -p, --adblock-port <port>      Use custom port for AdBlock server. It is
                                  highly recommended to use values higher than
                                  1024.
+  -u, --user-agent <user-agent>  User custom User-Agent HTTP header for all
+                                 network requests.
+  --threads <count>              Specify number of threads. Use --help to see
+                                 the maximum allowed number of threads.
 
 Arguments:
   urls                           List of URL addresses pointing to individual
@@ -37,4 +40,4 @@ rssguard.exe "feed:https//archlinux.org/feeds/news"
 rssguard.exe "https://archlinux.org/feeds/news"
 ```
 
-In order to easily add the feed directly from your web browser of choice, without copying and pasting the URL manually, you have to open RSS Guard with feed URL passed as an argument. There are [browser extensions](https://addons.mozilla.org/en-US/firefox/addon/open-with/) which will allow you to do it.
+In order to easily add the feed directly from your web browser of choice, without copying and pasting the URL manually, you have to open RSS Guard with feed URL passed as an argument. There are [browser extensions](https://addons.mozilla.org/en-US/firefox/addon/open-with/) which will allow you to do it.