New features:
- add firrtl parser
- add gsim example
- support gsim complete
- support internal signal parse for gsim
- test gsim Nutshell success
- readme: update gsim info
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Co-authored-by: Makiras <xieyunlonglong@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
