Add generate-docs command to build task

The Swift Docc has to run in a Linux container to be able to build the
documentation, as it needs access to the inotify.h header files.

Sources/TaskCLI/TaskCLI.docc/TaskCLI.md

@@ -4,7 +4,7 @@ The build tool for the Swift Inotify project.
 
 ## Overview
 
-`TaskCLI` is a small command-line executable (exposed as `task` in `Package.swift`) that automates project-level workflows. Its primary purpose is running the integration test suite inside a Linux Docker container, so you can validate the inotify-dependent code on the correct platform even when developing on macOS.
+`TaskCLI` is a small command-line executable (exposed as `task` in `Package.swift`) that automates project-level workflows. Its primary purpose is running integration tests and generating documentation inside Linux Docker containers, so you can validate inotify-dependent code on the correct platform even when developing on macOS.
 
 ### Running the Tests
 
@@ -19,6 +19,16 @@ This launches a `swift:latest` Docker container with the repository mounted at `
 
 The container is started with `--security-opt systempaths=unconfined` so that the limit tests can write to `/proc/sys/fs/inotify/*`.
 
+### Generating Documentation
+
+```bash
+swift run task generate-docs
+```
+
+This copies the project to a temporary directory, injects the `swift-docc-plugin` dependency via `swift package add-dependency` (if absent), and runs documentation generation inside a `swift:latest` Docker container. The resulting static sites are written to `./public/inotify/` and `./public/taskcli/`, ready for deployment to GitHub Pages.
+
+The working tree is never modified — all changes happen in the temporary copy, which is cleaned up automatically.
+
 ### Verbosity
 
 Pass one or more `-v` flags to increase log output:
@@ -40,7 +50,12 @@ Docker must be installed and running on the host machine. The container uses the
 
 - ``Command``
 - ``TestCommand``
+- ``GenerateDocsCommand``
 
 ### Configuration
 
 - ``GlobalOptions``
+
+### Errors
+
+- ``GenerateDocsError``