Added esdoc support

Author: Manjiri Tapaswi

.esdoc.json

@@ -0,0 +1,13 @@
+{
+    "source": "./lib",
+    "destination": "./docs",
+    "plugins": [
+      {
+        "name": "esdoc-coverage-plugin",
+        "option": {
+          "enable": true,
+          "kind": ["class", "method", "member", "get", "set", "constructor", "function", "variable"]
+        }
+      }
+    ]
+  }

.gitignore

@@ -1,3 +1,4 @@
 node_modules/
 .DS_Store
 npm-debug.log
+docs

CONTRIBUTING.md

@@ -137,6 +137,7 @@ Generally, we follow the style guidelines as suggested by the official language.
 Please run your code through:
 
 - [ESLint](http://eslint.org/) with the standard style guide.
+- [esdoc](https://github.com/sendgrid/smtpapi-nodejs/blob/master/.github/USAGE.md) to check the documentation coverage of your added code.
 
 ## Creating a Pull Request<a name="creating_a_pull_request"></a>
 

USAGE.md

@@ -0,0 +1,11 @@
+# Documentation
+
+If you would like to auto-generate documentation of the packages, you can do so locally by running:
+```
+./node_modules/.bin/esdoc
+```
+Using the .esdoc.json file, esdoc will create documentation in the docs directory.
+
+## Checking docs coverage
+
+You will find a coverage.json file in the docs directory. This will contain information about the documentation coverage for each of the different files in this repo.

package.json

@@ -25,6 +25,10 @@
   "author": "scottmotte",
   "license": "BSD",
   "dependencies": {
+    "chai": "^2.3.0",
+    "esdoc": "^1.0.3",
+    "esdoc-coverage-plugin": "^1.1.0",
+    "esdoc-type-inference-plugin": "^1.0.1"
   },
   "devDependencies": {
     "mocha": "",