Bump npm version to 0.16.1.

Bump npm version to 0.16.0.

This minor version includes a major reorganization of the
repository/package, which took place mostly in PR #327, with additional
refinements in #886. There's always some risk to refactoring, and I
added several new type definitions, hence the minor version bump.

Why not a major version bump? I believe these changes should be mostly
backwards compatible, especially if you are not importing from any
nested directories like

  import es2020Plugin from "ast-types/def/es2020"

Since the `def/` directory has moved to `lib/def/`, you may need to
update your imports (a breaking change). However, you may be able to get
away with no changes if you're using a version of Node.js (or a bundler)
that understands the "exports" field in package.json:
#327 (comment)

Since I could be wrong about backwards compatibility, I will publish
v0.16.0 to npm using the "next" dist-tag initially, so we can make sure
benjamn/recast#1232 works. If breaking changes
come to light, we should be able to fix them before triggering a flood
of failing CI runs via dependabot/renovate/etc PRs.

Bump npm version to 0.15.2.

Bump npm version to 0.15.1.

Bump npm version to 0.15.0.

Bump npm version to 0.14.2.

Bump npm version to 0.14.1.

Bump npm version to 0.14.0.

The minor bump is due to the extent of the changes in PRs #375, #376,
and #377 (thanks to @gkz).

Bump npm version to 0.13.4 in preparation for publishing.

Bump npm version to 0.13.3 in preparation for publishing.