Change Svelte grammar source

[sebastinez]

Description

This PR changes the svelte grammar from the unmaintained umanghome/svelte-atom repo to sebastinez/svelte-atom maintained by me and with the goal to add the newest features, until it eventually will get replaced by a tree-sitter implementation.

The grammar replacement was done with the script/add-grammar script

Checklist:

• I am changing the source of a syntax highlighting grammar
  • Old: https://github.com/umanghome/svelte-atom
  • New: https://github.com/sebastinez/svelte-atom

[lildude]

LGTM. Thanks.

Note: this PR will not be merged until close to when the next release is made. See here for more details.

[sebastinez]

LGTM. Thanks.

Note: this PR will not be merged until close to when the next release is made. See here for more details.

Thanks @lildude, much appreciated