Update go.mod to use absolute module path.

[lemon-mint]

No description provided.

[Felixoid]

Without this patch the following breaks

> go install github.com/BobdaProgrammer/TermiSand@v1.0.1
go: github.com/BobdaProgrammer/TermiSand@v1.0.1: version constraints conflict:
        github.com/BobdaProgrammer/TermiSand@v1.0.1: parsing go.mod:
        module declares its path as: TermiSand
                but was required as: github.com/BobdaProgrammer/TermiSand