Improve dev experience: fix compiler version, add .gitignore

[roland-ewald]

Minor fixes to improve development (or debugging) experience: a .gitignore and an explicit configuration to use the latest stable rust version.

(Also fixes a minor typo.)

[ctsa]

Thanks @roland-ewald. Sorry for the delay, I realize that we haven't done a good job defining what level of developer support we should have for this tool, so I will see what we can do to clarify this.

For the moment, I can clarify that we do not directly develop on github, and only have batch source code updates to this repo on release, so it would be hard for us to accept any pull request directly. That said, I will see if we can include our regular .gitignore in the next source update and perhaps set an MSRV in the Cargo.toml to help with the items you point out here, in addition to some kind of policy clarification.

[ctsa]

Thanks again. I've added the corresponding clarifications here:

cb77099

[roland-ewald]

@ctsa Many thanks! 🚀 Good to know how this is being managed going forward. I just opened the PR because these changes seemed to be low-hanging fruit (and allow easier troubleshooting and debugging by others, which should make it easier to give feedback).

BTW any chance that PacificBiosciences/pbmm2#20 might be looked at, too? 😅 I've noticed that you wrote the other open PR there, that's why I'm asking. It's the same category of simple fix that avoids frustrations when troubleshooting.