Clarify docs

Author: anttiai

README.md

@@ -43,7 +43,7 @@ client.search('keyword', cb);
 ## Search API
 
 The client provides following functions to execute search queries. To use the client library for indexing, 
-see [Indexing API](https://github.com/AddSearch/js-client-library#indexing-api) section.
+see [Indexing API](https://github.com/AddSearch/js-client-library#indexing-api).
 
 #### Fetch search results
 ```js
@@ -302,7 +302,7 @@ client.setJWT(token);
 
 #### Set API throttling
 ```js
-// Set API call throttle time in milliseconds. Default is 200.
+// Set Search API throttle time in milliseconds. Default is 200.
 client.setThrottleTime(500);
 ```
 
@@ -321,7 +321,7 @@ var client = new AddSearchClient('YOUR PUBLIC SITEKEY', 'YOUR SECRET KEY');
 The secret key can be found from AddSearch Dashboard's "Setup" > "Keys and installation" page.
 Always keep the key secret.
 
-Indexing API functions return promises.
+All Indexing API functions are Promise-based.
 
 
 ### Document ID
@@ -330,21 +330,21 @@ Document ID can be defined by the user, or it can be autogenerated when a docume
 
 ```js
 // ID defined by the user
-const doc = {
+const docWithDefinedId = {
   id: '1234',
-  ...
+  custom_fields: {}
 }
 
 // ID created from the URL field (md5 sum)
-const doc = {
+const docWithURL= {
   url: 'https://..', // id will be md5('https://..')
-  ...
+  custom_fields: {}
 }
 
 // ID will be generated automatically
-const doc = {
+const docWithAutogeneratedId = {
   // No id or url fields
-  ...
+  custom_fields: {}
 }
 ```