Compatibility with typst 0.12

[TabError]

The package wasn't updated to the new typst version 0.12.

When compiling one gets the following Warnings:

❯ typst compile script.typ 
warning: calling `query` with a location is deprecated
   ┌─ @preview/lemmify:0.1.6/src/util.typ:68:18
   │
68 │   let locations = query(selector(heading).before(loc), loc)
   │                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   │
   = hint: try removing the location argument

warning: calling `query` with a location is deprecated
   ┌─ @preview/lemmify:0.1.6/src/util.typ:72:15
   │
72 │     let numb = query(selector(heading).before(loc), loc).last().numbering
   │                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   │
   = hint: try removing the location argument

Additionally the contents of theorems and proof are centered and not left-aligned.

[TabError]

I add a merge request for this:
#34