chore: npmrc

[breautek]

Platforms affected

None

Motivation and Context

Adds .npmrc file that tells NPM to use NPM's official registry.

Progresses apache/cordova#299

Description

Testing

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[codecov-commenter]

Codecov Report

Merging #288 (7c700fa) into master (277dcc7) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #288   +/-   ##
=======================================
  Coverage   58.73%   58.73%           
=======================================
  Files           8        8           
  Lines         492      492           
=======================================
  Hits          289      289           
  Misses        203      203           

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[breautek]

All tests passed. Travis/appveyor is obsolete and will be removed in another PR, so ignoring.