📝 Modify README

README.md

@@ -1 +1,66 @@
-# serverless-plugin-subscription-filter
+# serverless-plugin-subscription-filter
+
+[![serverless](http://public.serverless.com/badges/v3.svg)](http://www.serverless.com)
+
+Serverless plugin to register AWS CloudWatchLogs subscription filter.
+
+## Installation
+
+`npm install --save-dev serverless-plugin-subscription-filter`
+
+```yaml
+plugins:
+  - serverless-plugin-subscription-filter
+```
+
+## Usage
+
+This plugin is  external serverless events.
+You can write settings like serverless events.
+
+```yaml
+functions:
+  hello:
+    handler: handler.hello
+    events:
+      - subscriptionFilter:
+          stage: prod
+          logGroupName: /cloud-trail
+          filterPattern: "{ $.errorMessage != '' }"
+```
+
+Supports also multiple subscription filter.
+
+```yaml
+functions:
+  hello:
+    handler: handler.hello
+    events:
+      - subscriptionFilter:
+          stage: prod
+          logGroupName: /cloud-trail
+          filterPattern: "{ $.errorMessage != '' }"
+      - subscriptionFilter:
+          stage: prod
+          logGroupName: /my-log-group
+          filterPattern: "{ $.errorMessage != '' }"
+  goobye:
+    handler: handler.goodbye
+    events:
+      - subscriptionFilter:
+          stage: dev
+          logGroupName: /my-log-group2
+          filterPattern: Exception
+```
+
+### About each properties
+
+|property|description|
+|:---:|:---:|
+|stage|The deployment stage with serverless. Sorry, only one subscription filter can be set for one LogGroup.|
+|logGroupName|The log group to associate with the subscription filter. |
+|filterPattern|The filtering expressions that restrict what gets delivered to the destination AWS resource. Sorry, if you want to use "{ $.xxx == yyy }" syntax, then surround ""(double quote).|
+
+## Future supports
+
+* Set IAM Role for subscription filter