docs: add --scope user to Claude Code examples in READMEs (#118)

Small followup to https://gitea.com/gitea/gitea-mcp/pulls/117. By using the user scope, the MCP server connection will be saved into the user's home directory, making it available for all repos, which is more useful than having to do this per-repo.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---------

Co-authored-by: hiifong <f@f.style>
Reviewed-on: https://gitea.com/gitea/gitea-mcp/pulls/118
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: hiifong <f@f.style>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>

README.md

@@ -38,7 +38,7 @@ Model Context Protocol (MCP) is a protocol that allows for the integration of va
 This method uses `go run` and requires [Go](https://go.dev) to be installed.
 
 ```bash
-claude mcp add --transport stdio gitea \
+claude mcp add --transport stdio --scope user gitea \
   --env GITEA_ACCESS_TOKEN=token \
   --env GITEA_HOST=https://gitea.com \
   -- go run gitea.com/gitea/gitea-mcp@latest -t stdio

README.zh-cn.md

@@ -38,7 +38,7 @@ Model Context Protocol (MCP) 是一种协议，允许通过聊天界面整合各
 此方式使用 `go run`，需要安装 [Go](https://go.dev)。
 
 ```bash
-claude mcp add --transport stdio gitea \
+claude mcp add --transport stdio --scope user gitea \
   --env GITEA_ACCESS_TOKEN=token \
   --env GITEA_HOST=https://gitea.com \
   -- go run gitea.com/gitea/gitea-mcp@latest -t stdio

README.zh-tw.md

@@ -38,7 +38,7 @@ Model Context Protocol (MCP) 是一種協議，允許透過聊天介面整合各
 此方式使用 `go run`，需要安裝 [Go](https://go.dev)。
 
 ```bash
-claude mcp add --transport stdio gitea \
+claude mcp add --transport stdio --scope user gitea \
   --env GITEA_ACCESS_TOKEN=token \
   --env GITEA_HOST=https://gitea.com \
   -- go run gitea.com/gitea/gitea-mcp@latest -t stdio