Update Localizable.xcstrings

Change button name to be more concise.

Replace this paragraph with a description of what this PR is changing or adding, and why. Consider including before/after screenshots.

List which issues are fixed by this PR. You must list at least one issue.

Pre-launch Checklist

[x] I read the Code of Conduct and followed the process outlined there for submitting PRs.
[ ] I listed at least one issue that this PR fixes in the description above.
[x] I updated/added relevant documentation (doc comments with ///).
[x] I updated README.md file with new version/info - if applicable.
[ ] I added new tests to check the change I am making or feature I am adding, or Hixie said the PR is test-exempt.
[ ] All existing and new tests are passing.