feat: Update example model and git commit shortcut model.

This commit updates the example config model used by Futago to "gemini-2.0-flash-thinking-exp".
It also updates the git commit shortcut to explicitly specify "gemini-2.0-flash-exp" as the model. This change ensures that the correct model is used for these functions.

README.md

@@ -176,7 +176,7 @@ Default is "tabnew".
 
 ```vim
 let g:futago_debug = v:true
-let g:futago_model = "gemini-1.5-flash-latest"
+let g:futago_model = "gemini-2.0-flash-thinking-exp"
 let g:futago_chat_path = '~/.cache/vim/futago/chat'
 let g:futago_log_file = '~/.cache/vim/futago/log/futago.log'
 let g:futago_history_db = '~/.cache/vim/futago/db/history.db'
@@ -198,7 +198,7 @@ nnoremap <Leader>fc <Cmd>call futago#start_chat({
   \ ],
   \ "humanPrompt": "yukimemi"
   \ })<CR>
-nnoremap <Leader>fg <Cmd>call futago#git_commit()<CR>
+nnoremap <Leader>fg <Cmd>call futago#git_commit({ "model": "gemini-2.0-flash-exp" })<CR>
 ```
 
 # License

doc/futago.txt

@@ -171,7 +171,7 @@ Example ~
 
 >
 	let g:futago_debug = v:true
-	let g:futago_model =  "gemini-1.5-flash-latest"
+	let g:futago_model =  "gemini-2.0-flash-thinking-exp"
 	let g:futago_chat_path = '~/.cache/vim/futago/chat'
 	let g:futago_log_file = '~/.cache/vim/futago/log/futago.log'
 	let g:futago_history_db = '~/.cache/vim/futago/db/history.db'
@@ -193,7 +193,7 @@ Example ~
 	  \ ],
 	  \ "humanPrompt": "yukimemi"
 	  \ })<CR>
-	nnoremap <Leader>fg <Cmd>call futago#git_commit()<CR>
+	nnoremap <Leader>fg <Cmd>call futago#git_commit({ "model": "gemini-2.0-flash-exp" })<CR>
 <
 
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