fix: urls don't encode characters

[abubakriz]

When a file url has certain symbols like number sign (#), it doesn't encode them, which makes the browser fail to navigate to the file, thinking it is a document section. This commit fixes that by encoding urls using the built-in encodeURIComponent function.

Fixes #205, vercel/serve#726, and vercel/serve#774

[AndyBitz]

@abubakriz thanks for the PR, but I don't think this would be the right fix.

Calling encodeURIComponent on the entire href, it'd also encode /, which is not desired.

Imagine if the href would be /my-folder/hello#world.txt, calling encodeURIComponent('/my-folder/hello#world.txt') returns %2Fmy-folder%2Fhello%23world.txt.

We most likely want to call encodeURIComponent on each section of the path before we construct the template.