integration-docs: Combine two macros that are always used together.

Edited the git-append-branches.md macro to match the previous
git-branches-additional-feature.md macro, and moved it inside the
webhook-url-with-bot-email.md macro, as it's only ever used
immediately after that macro.

docs/documentation/integrations.md

@@ -127,11 +127,6 @@ Here are a few common macros used to document Zulip's integrations:
   rendering, see **Step 4** of
   [the docs for Zulip's Codebase integration][codebase].
 
-- `{!git-append-branches.md!}` - This macro explains how to specify a list
-  of branches in the webhook URL to filter notifications in our Git-related
-  webhooks. For an example rendering, see the last paragraph of **Step 2**
-  in [the docs for Zulip's GitHub integration][github-integration].
-
 - `{!webhook-url-with-bot-email.md!}` - Used in certain non-webhook integrations
   to generate URLs of the form:
 

templates/zerver/integrations/include/git-append-branches.md

@@ -1,4 +0,0 @@
-You can also limit the notifications you receive to specific branches
-by appending `?branches=main,development` to the end of the URL,
-where `main` and `development` are the branches you'd like to be
-notified about.

templates/zerver/integrations/include/webhook-url-with-bot-email.md

@@ -7,3 +7,7 @@ Modify the parameters of the URL above, where `bot_email` is
 the bot's URL-encoded email address and `bot_api_key` is the
 bot's API key.  To URL-encode the email address, you just need
 to replace `@` in the bot's email address with `%40`.
+
+You can also limit the branches you receive notifications for by
+specifying them in a comma-separated list appended to the end of the
+URL, e.g., `&branches=main,development`.

zerver/webhooks/beanstalk/doc.md

@@ -5,7 +5,6 @@ Zulip supports both SVN and Git notifications from Beanstalk.
 1. {!create-an-incoming-webhook.md!}
 
     {!webhook-url-with-bot-email.md!}
-    {!git-append-branches.md!}
 
 1. On your repository's webpage, click on the **Settings**
    tab. Click on the **Integrations** tab, scroll down and click on

zerver/webhooks/bitbucket/doc.md

@@ -14,8 +14,6 @@ hook from the list presented and click **Add hook**.
 
 {!webhook-url-with-bot-email.md!}
 
-{!git-append-branches.md!}
-
 By default, notifications are sent to the `commits` channel. To
 send notifications to a different channel, append
 `?stream=channel_name` to the URL.