chore: Update pullrequest template provider check

* Replaced the provider support table with a checklist format that is
  easier to read and update than emojis.
* Updated "Gitea" entry to "Gitea/Forgejo" since forgejo is going to
  be our preferred Gitea fork (for fedora support in the future).
* Refined wording regarding provider documentation updates.

Signed-off-by: Chmouel Boudjnah <[email protected]>

Author: chmouel

.github/pull_request_template.md

@@ -20,13 +20,11 @@
 
 - If adding a provider feature, fill in the following details:
 
-| Git Provider          | Supported |
-|-----------------------|-----------|
-| GitHub App            | ✅️        |
-| GitHub Webhook        | ❌️        |
-| Gitea                 | ❌️        |
-| GitLab                | ❌️        |
-| Bitbucket Cloud       | ❌️        |
-| Bitbucket Data Center | ❌️        |
-
-  (update the documentation accordingly)
+  - [ ] GitHub App
+  - [ ] GitHub Webhook
+  - [ ] Gitea/Forgejo
+  - [ ] GitLab
+  - [ ] Bitbucket Cloud
+  - [ ] Bitbucket Data Center
+
+  (update the provider documentation accordingly)