Add `rustfmt.toml`file

[jquesada2016]

Currently, the project does not have a rustfmt.toml, causing inconsistant formatting for users who contribute with a non-default global rustfmt.toml file.

[cla-bot[bot]]

We require contributors to sign our Contributor License Agreement, and we don't have yours on file. In order for us to review and merge your code, please send a signing request to cla-requests@gdlauncher.com and add your github handle to contributors list.

[linear[bot]]

GDL-374 Add `rustfmt.toml`

Currently, the project does not have a `rustfmt.toml`, causing inconsistant formatting for users who contribute with a non-default global `rustfmt.toml` file.

[iluminn]

Can we

1. keep the line width at 100
2. wait until the export pr is merged and any other backend prs going now

[jquesada2016]

Sure. Setting the width to 100 will remove all merge conflicts, since rustfmt won't touch anything. I set it to 80 to avoid line wrapping/scrolling.

[cla-bot[bot]]

We require contributors to sign our Contributor License Agreement, and we don't have yours on file. In order for us to review and merge your code, please send a signing request to cla-requests@gdlauncher.com and add your github handle to contributors list.

[cla-bot[bot]]

We require contributors to sign our Contributor License Agreement, and we don't have yours on file. In order for us to review and merge your code, please send a signing request to cla-requests@gdlauncher.com and add your github handle to contributors list.

[jquesada2016]

I really think max_width should be set to 80, otherwise there can be a lot of vertical scrolling or line wrapping, in this case for me, but also for users who work with more than one window open at a time.