regenerate docs

Author: benmccann

docs/README.md

@@ -1,4 +1,4 @@
-**imagetools** • [**Docs**](modules.md)
+**imagetools** • [**Docs**](_media/modules.md)
 
 # Imagetools documentation
 
@@ -8,13 +8,13 @@ unclear!
 
 ## Basic
 
-- [Why?](guide/why.md)
-- [Install](guide/install.md)
-- [Getting Started](guide/getting-started.md)
-- [All directives](directives.md)
+- [Why?](_media/why.md)
+- [Install](_media/install.md)
+- [Getting Started](_media/getting-started.md)
+- [All directives](_media/directives.md)
 
 ## Dive deeper
 
-- [Extend Imagetools](guide/extending.md)
+- [Extend Imagetools](_media/extending.md)
 - [Sharp's documentation](https://sharp.pixelplumbing.com)
-- [Caching](guide/caching.md)
+- [Caching](_media/caching.md)

docs/_media/caching.md

@@ -0,0 +1,46 @@
+# Caching
+
+To speed up a build pipeline with many images, the generated images can be cached on disk. 
+If the source image changes, the cached images will be regenerated.
+
+## How to configure caching
+
+Caching is enabled by default and uses './node_modules/.cache/imagetools' as the cache directory. 
+You can disable caching or change the directory with options.
+
+```
+// vite.config.js, etc
+...
+    plugins: [
+      react(),
+      imagetools({
+        cache: {
+          enabled: true,
+          dir: './node_modules/.cache/imagetools'
+        }
+      })
+    ]
+...
+```
+
+## Cache retention to remove unused images
+
+When an image is no longer there or the transformation parameters change, the previously
+cached images will be removed after a configurable retention period.
+A value of `undefined` will disable this mechanism, which is the default.
+
+```
+// vite.config.js, etc
+...
+    plugins: [
+      react(),
+      imagetools({
+        cache: {
+          enabled: true,
+          dir: './node_modules/.cache/imagetools',
+          retention: 172800
+        }
+      })
+    ]
+...
+```