feat: add support matrix shortcode

Added a support matrix shortcode to the policy guide to indicate
which Git providers support specific features. This includes
GitHub App, GitHub Webhook, Gitea, GitLab, Bitbucket Cloud, and
Bitbucket Server.

Update pull_request default template so that the dev can communicate it
in the pull_request.

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

Author: chmouel

.github/pull_request_template.md

@@ -18,3 +18,14 @@ your descriptive commit message(s)! -->
 - [ ] 🎁 If feasible, please check if an end-to-end test can be added. See [README](https://github.com/openshift-pipelines/pipelines-as-code/blob/main/test/README.md) for more details.
 
 - [ ] 🔎 If there's any flakiness in the CI tests, don't necessarily ignore it. It's better to address the issue before merging, or provide a valid reason to bypass it if fixing isn't possible (e.g., token rate limitations).
+
+- If you are adding a provider feature, please fill up the following details which provider this feature supports:
+
+  - [ ] GitHub
+  - [ ] GitHub Webhook
+  - [ ] Gitea
+  - [ ] Gitlab
+  - [ ] Bitbucket Cloud
+  - [ ] Bitbucket Server/DC
+
+  (make sure to update the documentation accordingly)

docs/content/docs/guide/policy.md

@@ -9,6 +9,8 @@ Pipelines-as-Code uses policies to control which actions can be performed by
 users who belong to specific teams within an organization, as defined on GitHub
 or other supported Git providers (currently GitHub and Gitea).
 
+{{< support_matrix github_app="true" github_webhook="true" gitea="true" gitlab="false" bitbucket_cloud="false" bitbucket_server="false" >}}
+
 ## Supported Actions
 
 * `pull_request` - This action triggers the CI in Pipelines-as-Code. Specifying

docs/layouts/shortcodes/support_matrix.html

@@ -0,0 +1,49 @@
+{{ $gitlabSupported := .Get "gitlab" }} {{ $githubAppSupported := .Get
+"github_app" }} {{ $githubWebhookSupported := .Get "github_webhook" }} {{
+$giteaSupported := .Get "gitea" }} {{ $gitlabSupported := .Get "gitlab" }} {{
+$bitbucketCloudSupported := .Get "bitbucket_cloud" }} {{
+$bitbucketServerSupported := .Get "bitbucket_server" }}
+
+<blockquote class="book-hint warning">
+  <p>This feature is supported on the following providers</p>
+  <table>
+    <thead>
+      <tr>
+        <th>Git Provider</th>
+        <th>Supported</th>
+      </tr>
+    </thead>
+    <tbody>
+      <tr>
+        <td>GitHub App</td>
+        <td>{{ if eq $githubAppSupported "true" }}✅️{{ else }}❌️{{ end }}</td>
+      </tr>
+      <tr>
+        <td>GitHub Webhook</td>
+        <td>
+          {{ if eq $githubWebhookSupported "true" }}✅️{{ else }}❌️{{ end }}
+        </td>
+      </tr>
+      <tr>
+        <td>Gitea</td>
+        <td>{{ if eq $giteaSupported "true" }}✅️{{ else }}❌️{{ end }}</td>
+      </tr>
+      <tr>
+        <td>GitLab</td>
+        <td>{{ if eq $gitlabSupported "true" }}✅️{{ else }}❌️{{ end }}</td>
+      </tr>
+      <tr>
+        <td>Bitbucket Cloud</td>
+        <td>
+          {{ if eq $bitbucketCloudSupported "true" }}✅️{{ else }}❌️{{ end }}
+        </td>
+      </tr>
+      <tr>
+        <td>Bitbucket Server</td>
+        <td>
+          {{ if eq $bitbucketServerSupported "true" }}✅️{{ else }}❌️{{ end }}
+        </td>
+      </tr>
+    </tbody>
+  </table>
+</blockquote>