golangci lint (#822)

* chore: add dupword to golangci-lint

It checks for duplicate words in the source code.

Added in golangci-lint v1.50.0

Also, fix the reported issues

* chore: add usestdlibvars to golangci-lint

A linter that detect the possibility to use variables/constants from the Go standard library.

Added in golangci-lint v1.48.0

Also, fix the reported issue

* chore: add mirror to golangci-lint

A linter that reports wrong mirror patterns of bytes/strings usage.

Added in golangci-lint v1.53.0

Also, fix the reported issue

* chore: add thelper to golangci-lint

This linter checks tests helpers which is not start with t.Helper() method.

Added in golangci-lint v1.34.0

Also, fix the reported issues

chore: add mingw dep

chore: fix CC/CXX entries

test: fix invalid pkg case

fix: fallback to default config when syncing

#798

chore: fix Appveyor

refactor: use `pterm.Fuzzy` instead of `Gray`

#796.

fix: ensure `StylesPath` is created with `sync`

fix: use `utf8.RuneCountInString` for offsets

chore: bump twine to v0.10.0