Merge pull request #453 from PyThaiNLP/dev

Update CONTRIBUTING.md

Author: bact

CONTRIBUTING.md

@@ -55,6 +55,7 @@ automatically from "docstring" comments in source code. This means the comment
 section in the source code is important for the quality of documentation.
 - A docstring should start with one summary line, ended the line with a full stop (period),
 then followed by a blank line before the start new paragraph.
+- A commit to release branches (e.g. `2.2`, `2.1`) with a title **"(build and deploy docs)"** (without quotes) will trigger the system to rebuild the documentation files and upload them to the website https://pythainlp.github.io/docs.html
 
 
 ## Testing
@@ -95,6 +96,9 @@ Make sure the same tests pass on Travis CI and AppVeyor.
   bumpversion build
   #current_version = 2.2.2-dev2
 
+  bumpversion release
+  #current_version = 2.2.2-beta0
+  
   bumpversion release
   #current_version = 2.2.2
 
@@ -110,11 +114,13 @@ Make sure the same tests pass on Travis CI and AppVeyor.
   bumpversion major
   #current_version = 3.0.0-dev0
 
+  bumpversion release
+  #current_version = 3.0.0-beta0
+
   bumpversion release
   #current_version = 3.0.0
   ```
 
-
 ## Credits
 
 <a href="https://github.com/PyThaiNLP/pythainlp/graphs/contributors">