Add config option to enable or disable log executed SQL (#3726)

* add config option to enable or disable log executed SQL

* rename ShowSQL to LogSQL

docs/content/doc/advanced/config-cheat-sheet.en-us.md

@@ -121,6 +121,7 @@ Values containing `#` or `;` must be quoted using `` ` `` or `"""`.
 - `PASSWD`: **\<empty\>**: Database user password. Use \`your password\` for quoting if you use special characters in the password.
 - `SSL_MODE`: **disable**: For PostgreSQL only.
 - `PATH`: **data/gitea.db**: For SQLite3 only, the database file path.
+- `LOG_SQL`: **true**: Log the executed SQL.
 
 ## Indexer (`indexer`)
 

docs/content/doc/advanced/config-cheat-sheet.zh-cn.md

@@ -80,6 +80,7 @@ menu:
 - `PASSWD`: 数据库用户密码。
 - `SSL_MODE`: PostgreSQL数据库是否启用SSL模式。
 - `PATH`: Tidb 或者 SQLite3 数据文件存放路径。
+- `LOG_SQL`: **true**: 显示生成的SQL，默认为真。
 
 ## Security (`security`)