Update Gitea documents

docs/docs/installation/gitea.md

@@ -0,0 +1,46 @@
+## Run a Gitea webhook server
+
+1. In Gitea create a new user and give it "Reporter" role ("Developer" if using Pro version of the agent) for the intended group or project.
+
+2. For the user from step 1. generate a `personal_access_token` with `api` access.
+
+3. Generate a random secret for your app, and save it for later (`webhook_secret`). For example, you can use:
+
+```bash
+WEBHOOK_SECRET=$(python -c "import secrets; print(secrets.token_hex(10))")
+```
+
+4. Clone this repository:
+
+```bash
+git clone https://github.com/qodo-ai/pr-agent.git
+```
+
+5. Prepare variables and secrets. Skip this step if you plan on setting these as environment variables when running the agent:
+1. In the configuration file/variables:
+    - Set `config.git_provider` to "gitea"
+
+2. In the secrets file/variables:
+    - Set your AI model key in the respective section
+    - In the [Gitea] section, set `personal_access_token` (with token from step 2) and `webhook_secret` (with secret from step 3)
+
+6. Build a Docker image for the app and optionally push it to a Docker repository. We'll use Dockerhub as an example:
+
+```bash
+docker build -f /docker/Dockerfile -t pr-agent:gitea_app --target gitea_app .
+docker push codiumai/pr-agent:gitea_webhook  # Push to your Docker repository
+```
+
+7. Set the environmental variables, the method depends on your docker runtime. Skip this step if you included your secrets/configuration directly in the Docker image.
+
+```bash
+CONFIG__GIT_PROVIDER=gitea
+GITEA__PERSONAL_ACCESS_TOKEN=<personal_access_token>
+GITEA__WEBHOOK_SECRET=<webhook_secret>
+GITEA__URL=https://gitea.com # Or self host
+OPENAI__KEY=<your_openai_api_key>
+```
+
+8. Create a webhook in your Gitea project. Set the URL to `http[s]://<PR_AGENT_HOSTNAME>/api/v1/gitea_webhooks`, the secret token to the generated secret from step 3, and enable the triggers `push`, `comments` and `merge request events`.
+
+9. Test your installation by opening a merge request or commenting on a merge request using one of PR Agent's commands.