Add --global option for installing molt

[kyoh86]

Now the command shows the warning like this:

⚠️ `deno install` behavior will change in Deno 2. To preserve the current behavior use the `-g` or `--global` flag.

Maybe molt should be installed as global.

[hasundue]

Thanks! LGTM but something wrong with CI 👀
Very unlikely to be related to your change but let me figure it out before merging...

[hasundue]

Let me rebase the upstream change on CI and test it.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.13%. Comparing base (5c884f6) to head (fb12cba).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #165      +/-   ##
==========================================
- Coverage   86.30%   86.13%   -0.18%     
==========================================
  Files          10       10              
  Lines        1161     1161              
  Branches      206      205       -1     
==========================================
- Hits         1002     1000       -2     
- Misses        157      159       +2     
  Partials        2        2              

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[hasundue]

Token-less upload of Codecov only works on Windows, which is weird, but I'm fixing it on another PR.

@kyoh86 do you mind if your commit being merged as unverified? I'm lazy and not configured signing...

[hasundue]

OK let me do it without a permission cause I don't think it super important.