chore: prepare for 6.1 release

Author: wincent

doc/command-t.txt

@@ -943,7 +943,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 HISTORY                                                     *command-t-history*
 
-main (not yet released) ~
+6.1 (14 June 2025) ~
 
 - fix: teach buffer finder to see all buffers passed into Neovim as
   command-line arguments (https://github.com/wincent/command-t/issues/418).

lua/wincent/commandt/version.lua

@@ -3,8 +3,8 @@
 
 return {
   major = 6,
-  minor = 0,
+  minor = 1,
   patch = 0,
-  prerelease = 'b.1',
-  version = '6.0.0-b.1',
+  prerelease = '',
+  version = '6.1',
 }