added readme to the repo

Author: ap-atul

README.md

@@ -0,0 +1,108 @@
+## Signed URL Plugin
+
+This plugin allows generating a signed url for a file link/id. Useful when
+using with AWS S3 sign urls for private objects.
+
+## Basic Usage
+
+-   Register the plugin
+
+```js
+await server.register([
+    {
+        plugin: signedUrl,
+        options: {
+            getSignedUrl: (key: string): string => 'my_custom_sign', // takes in function to sign the id
+        },
+    },
+]);
+```
+
+-   Dummy response
+
+```json
+{
+    "file": "random_id",
+    "name": "this is a file"
+}
+```
+
+-   Create a lens using ramda for the above object
+
+```js
+const lens = R.lensProp<string, any>('file') // here file is the key from object
+```
+
+-   Use it in the route
+
+```js
+server.route({
+    method: 'GET',
+    path: '/sample',
+    options: {
+        handler: handler.performAction,
+        plugins: {
+            // define the plugin
+            signedUrl: {
+                // add the array of lenses for multiple keys
+                lenses: [lens],
+            },
+        },
+        ...
+    },
+});
+```
+
+-   Final response
+
+```json
+{
+    "file": "random_id_SIGNATURE", // this value will be updated
+    "name": "this is a file"
+}
+```
+
+### For nested objects
+
+```js
+{
+    name: "some name",
+    more: "some more data",
+    ...,
+    documents: [
+        {
+            asset: "thisisafile", // want to update this
+            other: "other details",
+            ...
+        }
+    ]
+}
+
+// notice we dont change the basic lens
+const lens = R.lensProp<string, any>('asset');
+
+// but we add extra options, pathToSource
+// you can add multiple layer of paths
+const path = R.lensPath(['documents']);
+
+// in route it looks like
+server.route({
+    method: 'GET',
+    path: '/sample',
+    options: {
+        handler: handler.performAction,
+        plugins: {
+            signedUrl: {
+                lenses: [lens],
+                pathToSource: path, // add the path to source
+            },
+        },
+        ...
+    },
+});
+```
+
+### Note
+
+-   It will work with single objects and arrays. `pathToSource` is optional field,
+    use when nested objects are to be updated.