remove meson ctags, as built-in one works fine, and add to gitignore

.gitignore

@@ -2,6 +2,7 @@ build/
 winbuild/
 osxbuild/
 .ctagsdb
+tags
 .*DS_Store
 __pycache__
 *.out

doc/DEVELOPMENT.rst

@@ -56,20 +56,20 @@ In general, things like ``for`` loops should have no spaces between the ``for``
 ``ctags`` Support
 '''''''''''''''''
 
-A ``.ctagsdb`` file can assist certain code editors (like ``vim``) with jump-to-definition support and other useful features. To generate a ``taisei/.ctagsdb`` file.
+A ``tags`` file can assist certain code editors (like ``vim``) with jump-to-definition support and other useful features. To generate a ``taisei/tags`` file.
 
 .. code:: sh
 
    ninja ctags -C build/
 
-You then have to let your editor know that a ``.ctagsdb`` file exists.
+You then have to let your editor know that a ``tags`` file exists.
 
 Using ``.vimrc`` as an example:
 
 .. code:: sh
 
    # this will walk the project directory until it finds a .ctagsdb file
-   set tags=.ctagsdb;
+   set tags=tags;
 
 Compiling Issues
 ----------------

meson.build

@@ -518,10 +518,6 @@ foreach bindist_target : bindist_targets
     )
 endforeach
 
-run_target('ctags',
-    command : ['ctags', '-R', '--exclude=.git', '-f', '.ctagsdb', join_paths(meson.source_root(), 'src')]
-)
-
 summary = '''
 
 Summary: