[IMPROVEMENT] (custom feeds json )

### Please confirm these before moving forward.

- [X] I have searched for my feature proposal and have not found a work-in-progress/duplicate/resolved/discarded issue.
- [X] This improvement refers to an existing feature. If you want to suggest a new feature, please use [this template](https://github.com/marticliment/WingetUI/issues/new?assignees=marticliment&labels=new-feature&projects=&template=feature-request.yml&title=%5BFEATURE+REQUEST%5D+%28Enter+your+description+here%29).
- [X] This improvement is not a bug. If you want to report a bug, please use [this template](https://github.com/marticliment/WingetUI/issues/new?assignees=marticliment&labels=bug&projects=&template=bug-issue.yml&title=%5BBUG%5D+%28Enter+your+description+here%29).

### Describe the improvement

https://github.com/mandiant/flare-vm/issues/578 , [bosxstarter runs can be slow , and anything not on vm list one wants ...
some vm templates for reversing malware a tad dated but the pkg feeds to json nice vm takes some time to build , and can export to pkg set parallel for speed/ more tools added to vm ie raddare/Rizin etc.. beyond the defecto setup ]

[flarevm templating is a sacrificial lamb anyway suspect phishing outlook.eml /suspect pdf in malware ? if the saved state vm blows no biggy/roll back nicety of adding uniget one can add a json of ones own extras to build out vm repeatable ]

[choco sources add -n="vm-packages" -s "$desktopPath;.;https://www.myget.org/F/vm-packages/api/v2;https://myget.org/F/vm-packages/api/v2" --priority 1 ... ]

for uniget choco community can add weights/priority ie flare-vm , community , _"my-choco.mycorp.net/my-iis/rss"_

in vm sometimes choco sources wont show up... sometimes...
community 1st ... 2nd vm feeds

Aux.. or corp repo to **choco-custom-repos.json** out ie azure/intune choco 4 biz custom repo... / https://docs.chocolatey.org/en-us/guides/organizations/set-up-chocolatey-server/

in vm the choco list gets fickle or wont show / at times ...

Add the Extras bucket: Run scoop bucket add extras
Add the rasa bucket: Run scoop bucket add rasa https://github.com/rasa/scoops.git
one can export to *-feeds-json for import/export

scoop feeds cli yes can be done but likewise add feeds via wingetui/unigetui / export to unigetui on other machines ...

### Describe how this improvement could help users

one can export any custom feeds to a *-feeds.json ie scoop-custom , choco-custom-feeds.json etc...