(refs gitbucket#665)Fix markdown format

Author: takezoe

doc/activity.md

@@ -1,3 +1,5 @@
+Activity Timeline
+========
 GitBucket records several types of user activity to ```ACTIVITY``` table. Activity types are shown below:
 
 type              | message                                              | additional information

doc/auto_update.md

@@ -1,5 +1,5 @@
-# Automatic Schema Updating
-
+Automatic Schema Updating
+========
 GitBucket uses H2 database to manage project and account data. GitBucket updates database schema automatically in the first run after the upgrading.
 
 To release a new version of GitBucket, add the version definition to the [servlet.AutoUpdate](https://github.com/takezoe/gitbucket/blob/master/src/main/scala/servlet/AutoUpdateListener.scala) at first.

doc/comment_action.md

@@ -1,5 +1,5 @@
-# About Action in Issue Comment
-
+About Action in Issue Comment
+========
 After the issue creation at GitBucket, users can add comments or close it.
 The details are saved at ```ISSUE_COMMENT``` table.
 

doc/directory.md

@@ -1,5 +1,5 @@
-# Directory Structure
-
+Directory Structure
+========
 GitBucket persists all data into __HOME/.gitbucket__ in default (In 1.9 or before, HOME/gitbucket is default).
 
 This directory has following structure:

doc/how_to_run.md

@@ -1,4 +1,5 @@
-# How to run from the source tree
+How to run from the source tree
+========
 
 for Testers
 --------

doc/notification.md

@@ -1,4 +1,5 @@
-# Notification Email
+Notification Email
+========
 
 GitBucket sends email to target users by enabling the notification email by an administrator.
 

doc/readme.md

@@ -1,10 +1,10 @@
-# Developer's Guide
-
+Developer's Guide
+========
  * [How to run from source tree](how_to_run.md)
  * [Directory Structure](directory.md)
- * [Mapping and Validation](mapping_and_validation.md)
- * [Authentication in Controller](authentication.md)
- * [About Action in Issue Comment](comment_actionb.md)
+ * [Mapping and Validation](validation.md)
+ * Authentication in Controller (not yet)
+ * [About Action in Issue Comment](comment_action.md)
  * [Activity Types](activity.md)
  * [Notification Email](notification.md)
  * [Automatic Schema Updating](auto_update.md)

doc/mapping_and_validation.md renamed to doc/validation.md

@@ -1,5 +1,5 @@
-# Mapping and Validation
-
+Mapping and Validation
+========
 GitBucket uses [scalatra-forms](https://github.com/takezoe/scalatra-forms) to validate request parameters and map them to the scala object. This is inspired by Play2 form mapping / validation.
 
 At first, define the mapping as following: