Should make signature verification instructions more beginner-friendly

In the section, "How to verify GPG signatures", there is the following:

In order to be able to verify GPG signatures, you need to import the public key of the signer. Electrum binaries are signed with ThomasV's public key. On Linux, you can import that key using the following command: gpg --import ThomasV.asc.

This is a little unclear. Someone who doesn't know how to use GnuPG might not realize that "ThomasV.asc" is just a placeholder for however they input the key, as this Reddit post demonstrates. I suggest rewriting it to make it clearer. Also, watch the order of instructions, as it appears to ask them to verify the signature before importing the key.

Locate the “How to verify GPG signatures” section in the website source and read the current verification instructions. Rewrite the wording so the key-import step comes first and makes clear that ThomasV.asc represents the user's input or downloaded key file; done means a beginner can follow the sequence without interpreting the filename as literal.