Added docs for agit-setup

docs/content/doc/usage/agit-support.en-us.md

@@ -0,0 +1,57 @@
+---
+date: "	2022-09-01T20:50:42+0000"
+title: "Usage: Agit Setup"
+slug: "agit-setup"
+weight: 12
+toc: false
+draft: false
+menu:
+  sidebar:
+    parent: "usage"
+    name: "Agit Setup"
+    weight: 12
+    identifier: "agit-setup"
+---
+
+# Agit Setup
+
+In Gitea `1.13`, support for [agit](https://git-repo.info/en/2020/03/agit-flow-and-git-repo/) was added.
+
+## Creating PR with Agit
+Agit allows creating a PR while pushing code to the remote repo. This requires using a speacial command refspec.
+
+- `HEAD`
+
+  Target branch
+
+- `refs/<for|drafts|for-review>/`
+
+  Target PR Type.
+  * `for` - Normal PR
+  * `draft` - Draft PR
+  * `for-review` - Generate a PR ID for updating existing PR.
+
+- `<target-branch>/<session>`
+
+  Target remote branch to open a PR.
+
+- `-o <topic|title|description>`
+
+  Options for the PR
+  * `title` - Title of the PR.
+  * `topic` - Topic of the PR.
+  * `description` - Description of the PR. (Contents in Markdown format)
+
+## Examples
+
+Example of pushing a repo with a PR:
+
+```shell
+git push origin HEAD:refs/for/master
+```
+
+Example of pushing a repo with a PR `topic`, `title` and `description`:
+
+```shell
+git push origin HEAD:refs/for/master -o topic="Topic of my PR" -o title="Title of the PR" -o description="# The PR Description\nThis can be markdown formatted.\n[x] Ok"
+```