Enables code snippet previews

[bencmbrook]

This commit removes the slash before the hash (/#L9 --> #L9). Github permalinks should not include this slash before the hash (the slash still works for linking but breaks code snippet previews)

Effect of change:

Pasting a permalink before
https://github.com/t-mrt/copy-github-url/blob/b7a936b43d455c13effe76a1b27a6f65732b8e85/src/copy-github-URL.ts/#L43

and after

copy-github-url/src/copy-github-URL.ts

Line 43 in b7a936b

const u = url.parse(`https://${args.domain}/${args.repository}/blob/${args.commit}/${args.filePath}/#${L}`);