Remove no break space character that messes up header

See http://gitversion.readthedocs.io/en/latest/configuration/ where header "Configuration" is not properly formatted.

Removing \ufeff (nbsp) fixes this.

Author: serra

docs/configuration.md

@@ -1,4 +1,4 @@
-# Configuration
+# Configuration
 GitVersion 3.0 is mainly powered by configuration and no longer has branching
 strategies hard coded.
 
@@ -289,4 +289,4 @@ Indicates this branch config represents develop in GitFlow.
 Indicates this branch config represents a release branch in GitFlow.
 
 ### is-mainline
-When using Mainline mode, this indicates that this branch is a mainline. By default support/ and master are mainlines.
+When using Mainline mode, this indicates that this branch is a mainline. By default support/ and master are mainlines.