Caniuse: Change links to the browser-compat-data repo to point to branch `main`

[Schweinepriester]

For example https://caniuse.com/mdn-css_types_image_image-set in the Feedback tab

For corrections/updates, see the browser-compat-data Contributing docs and the support data for this feature.

both links point to …/master/… which leads to the (imho distracting) notification that you've been redirected:

(Also linking to main would be more correct)

Therefore please change those and possible other links to the browser-compat-data repo to point to branch main :)

[Fyrd]

Done! Thanks for pointing that out.