Implement actions badge svgs (#28102)

replace #27187 
close #23688
The badge has two parts: label(workflow name) and message(action
status). 5 colors are provided with 7 statuses.
Color mapping:
```go
var statusColorMap = map[actions_model.Status]string{
	actions_model.StatusSuccess:   "#4c1",    // Green
	actions_model.StatusSkipped:   "#dfb317", // Yellow
	actions_model.StatusUnknown:   "#97ca00", // Light Green
	actions_model.StatusFailure:   "#e05d44", // Red
	actions_model.StatusCancelled: "#fe7d37", // Orange
	actions_model.StatusWaiting:   "#dfb317", // Yellow
	actions_model.StatusRunning:   "#dfb317", // Yellow
	actions_model.StatusBlocked:   "#dfb317", // Yellow
}
```
preview:

![1](5465cbaf-23cd-4437-9848-2738c3cb8985)

![2](ec393d26-c6e6-4d38-b72c-51f2494c5e71)

![3](3edb4fdf-1b08-4a02-ab2a-6bdd7f532fb2)

![4](8c189de2-2169-4251-b115-0e39a52f3df8)

![5](3fe22c73-c2d7-4fec-9ea4-c501a1e4e3bd)

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>
Co-authored-by: delvh <dev.lh@web.de>

docs/content/usage/badge.en-us.md

@@ -0,0 +1,37 @@
+---
+date: "2023-02-25T00:00:00+00:00"
+title: "Badge"
+slug: "badge"
+sidebar_position: 11
+toc: false
+draft: false
+aliases:
+  - /en-us/badge
+menu:
+  sidebar:
+    parent: "usage"
+    name: "Badge"
+    sidebar_position: 11
+    identifier: "Badge"
+---
+
+# Badge
+
+Gitea has its builtin Badge system which allows you to display the status of your repository in other places. You can use the following badges:
+
+## Workflow Badge
+
+The Gitea Actions workflow badge is a badge that shows the status of the latest workflow run.
+It is designed to be compatible with [GitHub Actions workflow badge](https://docs.github.com/en/actions/monitoring-and-troubleshooting-workflows/adding-a-workflow-status-badge).
+
+You can use the following URL to get the badge:
+
+```
+https://your-gitea-instance.com/{owner}/{repo}/actions/workflows/{workflow_file}?branch={branch}&event={event}
+```
+
+- `{owner}`: The owner of the repository.
+- `{repo}`: The name of the repository.
+- `{workflow_file}`: The name of the workflow file.
+- `{branch}`: Optional. The branch of the workflow. Default to your repository's default branch.
+- `{event}`: Optional. The event of the workflow. Default to none.