Improve clarity for camo proxy parameters (#21386)

Updates the Config Cheat Sheet for the `ALLWAYS` option in Camo proxy.

- Clarifies the behavior for true (both HTTP and HTTPS is proxied) vs
false (only HTTP is proxied)
- Minor grammar and typo improvements

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

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

@@ -537,9 +537,9 @@ Certain queues have defaults that override the defaults set in `[queue]` (this o
 ## Camo (`camo`)
 
 - `ENABLED`: **false**: Enable media proxy, we support images only at the moment.
-- `SERVER_URL`: **<empty>**: url of camo server, it **is required** if camo is enabled.
+- `SERVER_URL`: **<empty>**: URL of camo server, it **is required** if camo is enabled.
-- `HMAC_KEY`: **<empty>**: Provide the HMAC key for encoding urls, it **is required** if camo is enabled.
+- `HMAC_KEY`: **<empty>**: Provide the HMAC key for encoding URLs, it **is required** if camo is enabled.
-- `ALLWAYS`: **false**: Set to true to use camo for https too lese only non https urls are proxyed
+- `ALLWAYS`: **false**: Set to true to use camo for both HTTP and HTTPS content, otherwise only non-HTTPS URLs are proxied
 
 ## OpenID (`openid`)