Added shortcut to open chrome extension

[samagragupta]

Fixes #52

Checklist

• [x] I have read the Contribution & Best practices Guide and my PR follows them.
• [x] My branch is up-to-date with the Upstream branch.
• [x] I have added necessary documentation (if appropriate)

Changes proposed in this pull request:

PressingAlt+Shift+W the extension will open.

[samagragupta]

@mariobehling @0x48piraj Please review.