style(build): rename to `maxthon-packer.exe`

Rename `maxthon-packager.exe` to `maxthon-packer.exe`.

This closes #133.
feat(settings): remove "Others" tab

Move everything from "Others" section to "Interface",
move "Reset Settings" and "View localStorage" buttons to "Backup".
Remove "Others" tab completely.

This closes #157.
feat(opera meta): auto-update

Add `update-description` element to `config.xml`, add `https` update
config link to `package.json` under `extensionUpdateUrls.opera` key.

This commit targets #153.
docs(README): add a link to site

- project is alpha
- go to site to install
- we support browsers: ...

This closes #154.