[CARBONDATA-1599] Update pull request checklist

Remove title and description items from pull request checklist, add them to How to contribute document

This closes apache#1451

Author: chenliang613

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,13 +1,5 @@
-Be sure to do all of the following to help us incorporate your contribution
-quickly and easily:
-
- - [ ] Make sure the PR title is formatted like:
-   `[CARBONDATA-<Jira issue #>] Description of pull request`
-   
- - [ ] Make sure to add PR description including
-        
-        - the root cause/problem statement
-        - What is the implemented solution
+Be sure to do all of the following checklist to help us incorporate 
+your contribution quickly and easily:
 
  - [ ] Any interfaces changed?
 
@@ -16,13 +8,11 @@ quickly and easily:
  - [ ] Document update required?
 
  - [ ] Testing done
- 
         Please provide details on 
         - Whether new unit test cases have been added or why no new tests are required?
         - How it is tested? Please attach test report.
         - Is it a performance related change? Please attach the performance test report.
         - Any additional information to help reviewers in testing this change.
-         
+       
  - [ ] For large changes, please consider breaking it into sub-tasks under an umbrella JIRA. 
-                 
----
+

docs/How-to-contribute-to-Apache-CarbonData.md

@@ -152,9 +152,13 @@ $ git rebase -i origin/master
 Navigate to the CarbonData GitHub mirror to create a pull request. The title of the pull request
 should be strictly in the following format:
 ```
-[CARBONDATA-issue number>] Title of the pull request
+[CARBONDATA-JiraTicketNumer][FeatureName] Description of pull request    
 ```
-Please include a descriptive pull request message to help make the reviewer’s job easier.
+Please include a descriptive pull request message to help make the reviewer’s job easier:
+```
+ - The root cause/problem statement
+ - What is the implemented solution
+ ```
 
 If you know a good committer to review your pull request, please make a comment like the following.
 If not, don’t worry, a committer will pick it up.