csharpier extensions

[thomaslaich]

• add nixfmt-rfc-style
• flake update
• add fantomas (add fantomas #159)
• feat(programs): add templ (Add templ formatter #161)
• feat(programs): add opa (feat(programs): add opa #162)
• Fix elm-format
• Add changed examples/formatter-elm-format.toml
• Make elm-format includes configurable
• feat(programs): add dos2unix (feat(programs): add dos2unix #165)
• fix(programs): leptosfmt does not touch files anymore (fix(programs): leptosfmt does not touch files anymore #166)
• feat: add ts declaration extensions to ext.js (feat: add ts declaration extensions to ext.js #168)
• Add packer fmt formatter (Add packer fmt formatter #169)
• add includes and excludes options for csharpier