Made start of documentation

docs.json

@@ -0,0 +1,22 @@
+{
+  "name": "cached_network_image",
+  "sidebar": [
+    [
+      "CachedNetworkImage",
+      [
+        ["Overview", "/"]
+      ]
+    ],
+    ["CacheManager",
+      [
+        ["Overview", "/cache-manager"],
+        ["Caching rules", "/caching-rules"]
+      ]
+    ],
+    ["OctoImage",
+      [
+        ["Overview","/octo-image"]
+      ]
+    ]
+  ]
+}

docs/cache-manager.mdx

@@ -0,0 +1 @@
+TODO

docs/caching-rules.mdx

@@ -0,0 +1,4 @@
+# Caching rules
+
+It uses [cache-control](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control) headers to know if the cache is outdated (max-age and eTag).
+If it is outdated the cached version is shown directly and the server is requested for an update. If the server sends a new image it updates the image directly.

docs/index.mdx

@@ -0,0 +1,49 @@
+# Cached network image
+## How to use
+The CachedNetworkImage can be used directly or through the ImageProvider.
+Both the CachedNetworkImage as CachedNetworkImageProvider have minimal support for web. It currently doesn't include caching.
+
+With a placeholder:
+```dart
+CachedNetworkImage(
+    imageUrl: "http://via.placeholder.com/350x150",
+    placeholder: (context, url) => CircularProgressIndicator(),
+    errorWidget: (context, url, error) => Icon(Icons.error),
+ ),
+ ```
+
+ Or with a progress indicator:
+ ```dart
+CachedNetworkImage(
+    imageUrl: "http://via.placeholder.com/350x150",
+    progressIndicatorBuilder: (context, url, downloadProgress) =>
+            CircularProgressIndicator(value: downloadProgress.progress),
+    errorWidget: (context, url, error) => Icon(Icons.error),
+ ),
+ ```
+
+
+````dart
+Image(image: CachedNetworkImageProvider(url))
+````
+
+When you want to have both the placeholder functionality and want to get the imageprovider to use in another widget you can provide an imageBuilder:
+```dart
+CachedNetworkImage(
+  imageUrl: "http://via.placeholder.com/200x150",
+  imageBuilder: (context, imageProvider) => Container(
+    decoration: BoxDecoration(
+      image: DecorationImage(
+          image: imageProvider,
+          fit: BoxFit.cover,
+          colorFilter:
+              ColorFilter.mode(Colors.red, BlendMode.colorBurn)),
+    ),
+  ),
+  placeholder: (context, url) => CircularProgressIndicator(),
+  errorWidget: (context, url, error) => Icon(Icons.error),
+),
+```
+
+## How it works
+The cached network images stores and retrieves files using the [flutter_cache_manager](https://pub.dartlang.org/packages/flutter_cache_manager).

docs/octo-image.mdx

@@ -0,0 +1,4 @@
+# OctoImage
+
+CachedNetworkImage uses OctoImage under the hood. You can also use OctoImage directly to use the same placeholder logic for
+both cached and non-cached images.