Add co-author to existing package (Update e.json)

[axemonk]

Added co-author @michaelblyons

• I'm the package's author and/or maintainer.
• I have have read [the docs][1].
• I have tagged a release with a [semver][2] version number.
• My package repo has a description and a README describing what it's for and how to use it.
• My package doesn't add context menu entries. *
• My package doesn't add key bindings. **
• Any commands are available via the command palette.
• Preferences and keybindings (if any) are listed in the menu and the command palette, and open in split view.
• If my package is a syntax it doesn't also add a color scheme. ***
• If my package is a syntax it is named after the language it supports (without suffixes like "syntax" or "highlighting").

My package is an existing package adding support for syntax highlighting for Excel formulas (with aspirational support for GSheets and others).

There are no packages like it in Package Control.

[packagecontrol-bot]

Automated testing result: SUCCESS

Packages modified:
  - Excel formula

[michaelblyons]

I endorse this. I'm not sure if that was clear.

@axemonk You may want to edit the PR title to say that the change just adds a co-author to Excel formula.

[axemonk]

thanks for the heads up @michaelblyons. Done.