More WebSub doc (#5862)

* More WebSub doc

* UI for WebSub + more documentation
And spellcheck Frech

* Links to WebSub doc from readme

* Add link to WebSub doc in admin interface

* Fix checkbox

* Plural

1 files changed, 49 insertions, 5 deletions

diff --git a/docs/en/users/WebSub.md b/docs/en/users/WebSub.md
index e8499b8e5..86abcde20 100644
--- a/docs/en/users/WebSub.md
+++ b/docs/en/users/WebSub.md
@@ -7,20 +7,64 @@ for instance when a new article is available via RSS / ATOM.
 FreshRSS supports WebSub natively.
 Just like for the FreshRSS API to work from a mobile phone, supporting WebSub requires that your FreshRSS instance is routable (that is to say, with a public IP, that can be accessed from third-party servers).
 
-## Examples of feeds
+## WebSub terminology
 
-Many individual feeds and platforms already offer instant notifications through WebSub, such as:
-[Friendica instances](https://friendi.ca), WordPress (from WordPress.com or with [an extension](https://wordpress.org/plugins/pubsubhubbub/)), Blogger sites, Medium sites, etc.
+There are tree main concepts:
+
+* **publisher**: Web site publishing content such as RSS / ATOM feeds;
+* **subscriber**: Feed aggregator such as FreshRSS;
+* **hub**: Intermediate technical component in charge of notifying all subscribers instantly when a publisher has some new content.
+The same hub can serve several publishers and their subscribers.
+Some publishers have a built-in hub.
+
+## Enabling WebSub in FreshRSS
+
+FreshRSS supports WebSub natively, but requires a public address (read from the `base_url` configuration),
+and requires the `./FreshRSS/p/api/` folder to be publicly accessible (just like for other FreshRSS APIs).
+
+During the initial Web-based setup, support for WebSub is enabled if the server hosting FreshRSS appears to have a public address.
+In any case, check your `./data/config.php` for:
 
-## Test WebSub
+```php
+'base_url' => 'https://freshrss.example.net/',
+'pubsubhubbub_enabled' => true,
+```
+
+Additional logs about WebSub are available in `./FreshRSS/data/users/_/log_pshb.txt`
+
+## Test WebSub compatibility of your FreshRSS instance
 
 You can test that WebSub works properly in your FreshRSS instance with a service such as:
 
 * <http://push-tester.cweiske.de>
 
+When you create a new article, it should instantly be available in your FreshRSS instance.
+
+## Examples of feeds using WebSub
+
+Many individual feeds and platforms already offer instant notifications through WebSub, such as:
+[Friendica instances](https://friendi.ca), WordPress (from WordPress.com or with [an extension](https://wordpress.org/plugins/pubsubhubbub/)), Blogger sites, Medium sites, etc.
+
+## Test WebSub compatibility of an RSS / ATOM feed
+
+* <https://test.livewire.io> (for any feed)
+* <https://websub.rocks/publisher> (for feeds you control)
+
 ## Add WebSub to your RSS / ATOM feeds
 
-Your CMS (e.g. WordPress) might already offer WebSub as an option. Otherwise, you can make a solution that notifies a hub such as:
+Your CMS (e.g. WordPress) might already offer WebSub as an option, such as:
+
+* <https://wordpress.org/plugins/pushpress/>
+
+Otherwise, you can make a solution that notifies a hub, such as:
 
 * <https://websubhub.com>
 * <https://pubsubhubbub.appspot.com>
+
+Or even deploy your own hub, such as:
+
+* <https://github.com/flusio/Webubbub>
+
+## Test WebSub compatibility of a hub
+
+* <https://websub.rocks/hub/100>