Added docs for watcher plugin

Home.md

@@ -6,3 +6,5 @@ Welcome to the Wiki.
 
 - [com.noccy.apiclient](com.noccy.apiclient) - API catalog and request helper
 - [com.noccy.pdo](com.noccy.pdo) - PDO Database helpers
+- [com.noccy.watcher](com.noccy.watcher) - Run scripts when files are modified
+

com.noccy.watcher.md

@@ -0,0 +1,55 @@
+# Watcher Plugin
+
+This plugin is capable of replacing node/npm for some use cases. Its only job is to
+keep an eye on files, and do something useful when they are changed. This could
+for example be checking a scss- or less-file for changes and automatically compiling
+new css.
+
+The action can be any executable command or other accepted script command including
+the `@some-script` reference to defined scripts. Thus you can have a script named
+`make-css` (callable with `spark run make-css`) and also a watcher for the relevant
+files which in turn calls on `@make-css`!
+
+Be aware that the functionality currently differs somewhat depending on if the inotify
+extension is available. This will be fixed, but right now this is what you get:
+With inotify you can watch a lot of directories, but unrelated changes may trigger
+your rules. Without inotify you can watch *a few* files, but with a lot of files or
+wildcards you may run into trouble. However, only watched files will trigger the
+rule. So it all depends on if you want efficient but spontaneous, or slow but
+reliable!
+
+## Installation
+
+Global installation (recommended, requires SPARK_PLUGINS environment):
+
+1. Extract the plug into your global plugin directory (`$SPARK_PLUGINS`)
+2. Go to your project directory and run `spark plugin --enable com.noccy.watcher`
+
+Local installation:
+
+1. Extract the directory into `.spark/plugins`, like a savage.
+
+## Configuration
+
+Create the config file `.spark/watchers.json`:
+
+```json
+{
+  "watchers": []
+}
+```
+
+Add your rules as objects under the `watchers` key:
+
+```json
+{
+  "name": "Rebuild Stylesheets",
+  "initial-trigger": true,
+  "watch": [ "./templates/style.scss" ],
+  "actions": [ "@make-css" ]
+}
+```
+
+After saving, you should be able to run `spark watch`:
+
+    $ spark watch