Move actions as usage's subdirectory and update comparsion zh-cn version (#24719)

As title.

Co-authored-by: Giteabot <teabot@gitea.io>

docs/content/doc/usage/actions/overview.en-us.md

@@ -0,0 +1,55 @@
+---
+date: "2023-04-27T15:00:00+08:00"
+title: "Gitea Actions"
+slug: "usage/actions/overview"
+weight: 1
+draft: false
+toc: false
+menu:
+  sidebar:
+    parent: "actions"
+    name: "Overview"
+    weight: 1
+    identifier: "actions-overview"
+---
+
+# Gitea Actions
+
+Starting with Gitea **1.19**, Gitea Actions are available as a built-in CI/CD solution.
+
+**Table of Contents**
+
+{{< toc >}}
+
+## Name
+
+It is similar and compatible to [GitHub Actions](https://github.com/features/actions), and its name is inspired by it too.
+To avoid confusion, we have clarified the spelling here:
+
+- "Gitea Actions" (with an "s", both words capitalized) is the name of the Gitea feature.
+- "GitHub Actions" is the name of the GitHub feature.
+- "Actions" could refer to either of the above, depending on the context. So it refers to "Gitea Actions" in this document.
+- "action" or "actions" refer to some scripts/plugins to be used, like "actions/checkout@v3" or "actions/cache@v3".
+
+## Runners
+
+Just like other CI/CD solutions, Gitea doesn't run the jobs itself, but delegates the jobs to runners.
+The runner of Gitea Actions is called [act runner](https://gitea.com/gitea/act_runner), it is a standalone program and also written in Go.
+It is based on a [fork](https://gitea.com/gitea/act) of [nektos/act](http://github.com/nektos/act).
+
+Because the runner is deployed independently, there could be potential security issues.
+To avoid them, please follow two simple rules:
+
+- Don't use a runner you don't trust for your repository, organization or instance.
+- Don't provide a runner to a repository, organization or instance you don't trust.
+
+For Gitea instances used internally, such as instances used by enterprises or individuals, neither of these two rules is a problem, they are naturally so.
+However, for public Gitea instances, such as [gitea.com](https://gitea.com), these two rules should be kept in mind when adding or using runners.
+
+## Status
+
+Gitea Actions is still under development, so there may be some bugs and missing features.
+And breaking changes may be made before it's stable (v1.20 or later).
+
+If the situation changes, we will update it here.
+So please refer to the content here when you find outdated articles elsewhere.