fix: show -n/--network flag in --help output

[tansawit]

Add help_heading = "Network" to the global -n/--network arg so it renders in --help output. Currently it's the only non-hidden global arg without a help_heading, so it gets lost in the default Options group.

Fixes #345

[Slokh]

thanks!

[tansawit]

@Slokh pused a commit to resolve the fmt CI failure in the PR. But the remaining ones are still failing. Seems like it's it's because the PR comes from a fork and those workflows expect the branch to be available in tempo/wallet?

[Slokh]

@tansawit yeah we have this automatic changelogs thing we've been using internally, but this is a good test case for forks. so will use this PR to fix that up if you dont mind and get this in a bit later

https://github.com/tempoxyz/changelogs

[tansawit]

of course. let me know if I need to do anything or can help in any way 🫡