add docs

Signed-off-by: tison <[email protected]>

README.md

@@ -43,9 +43,11 @@ You will need to create the following secret. Use the credentials generated in t
 |--------------|------------------------------------------------------|
 |zuliprc       | The file content of the zuliprc obtained from step 2 |
 
-### Step 4 - Enable GitHub Pages
+### Step 4 - Enable GitHub Pages or set up base URL
 
-Go to `https://github.com/<username>/<repo-name>/settings/pages`, select `main` (or a branch of your choosing), and `/` as the folder. Save the changes.
+Go to `https://github.com/<username>/<repo-name>/settings/pages`, select `main` (or a branch of your choosing), and `/` as the folder. Save the changes. The base URL of the generated site will be resolved to GitHub Pages, i.e., `https://<username>.github.io/<repo-name>` or the configured custom domain name.
+
+Alternatively, you can configure the `base_url` option to populate the base URL without enabling GitHub Pages.
 
 ### Step 5 - Configure the streams you want to index
 
@@ -137,6 +139,7 @@ warned that the repository size may explode.
 
 Finally, verify that everything is working as expected. You can track the status of the action by visiting `https://github.com/<github-username>/<repo-name>/actions`. Once the initial run is completed, you should be able to visit the archive by opening the link provided at the end of the action run log. The link will generally be of the form `<github-username>.github.io/<repo-name>`, or `<your-personal-domain>/<repo-name>` if you have configured your own personal domain to point to GitHub pages.
 
+If you configure `base_url` option, you can track the status of the action by visiting the URL instead.
 
 ## Running zulip-archive without GitHub actions
 

action.yml

@@ -31,7 +31,7 @@ inputs:
     description: 'zuliprc of the Zulip bot'
     required: true
   site_url:
-    description: 'Base URL for the site'
+    description: 'Base URL for the site. If not configured, this action will try to resolve the base URL as GH pages.'
     required: false
 runs:
   using: 'docker'