feat: add support for optional dynamic route params

[mbhrznr]

tackles #1690.

this pr is a first attempt to support optional dynamic routes.
the file name convention is inspired by sveltekit's established convention.

the feature can be tested in the primary fixture by running:

deno task fixture

once started, navigate to /i18n/lang and /i18n/:lang/lang.

[mbhrznr]

would add some documentation once we've settled on the general approach.

[marvinhagemeister]

This is fantastic! Going with the way Svelte does it makes a lot of sense. Like this much more then the original proposed [...id]. Found one additional case to account for, but other than that it looks really good and I'm excited to have this in Fresh 👍

[mbhrznr]

would it make sense to refactor www's docs/[...slug].tsx to make use of the new concept?
or would you prefer to have this tackled in another pr?

[marvinhagemeister]

would it make sense to refactor www's docs/[...slug].tsx to make use of the new concept?
or would you prefer to have this tackled in another pr?

Let's tackle that in another PR

[marvinhagemeister]

Awesome, this is great!

[marvinhagemeister]

Awesome, this is great!