Add hint to GNUPGHOME environment variable (#20134)
Add hint to GNUPGHOME environment variable (#20134)

* Add hint for GNUPGHOME environment variable

With #19732, the default location for the `.gnupg` folder has changed. To mitigate this breaking change, users can specify the home directory for gnupg via `$GNUPGHOME` environment variable to keep using their current location.

* Update docs/content/doc/advanced/signing.en-us.md

Co-authored-by: wxiaoguang <afddda5b6ea4f5ea4386c1c8946f240cce9ffa2e@gmail.com>

Co-authored-by: wxiaoguang <afddda5b6ea4f5ea4386c1c8946f240cce9ffa2e@gmail.com>
Co-authored-by: Lunny Xiao <0b0704cdf8f0790c6f1df1f74c38be95a8917ed2@gmail.com>
Co-authored-by: John Olheiser <2efb384cc32e2c1c40c2368e43e7c46e52df9a2c@gmail.com>
Co-authored-by: zeripath <6a547fdd28db89120bdd70d4af1f9ba672ccd43a@cantab.net>
go-gitea/gitea,go-gitea/gitea,go-gitea/gitea