~mna/siberian

hm not sure if debug works as expected
add Debug func, incomplete
figure out how to do the visit matcher, test and and not
add MatcherVisitor interface and implementation
add And matcher, fix escape in json parser
add some benchmark to compare with stdlib
implement json grammar, test some parsing values
add Matches API func, start thinking about visiting Matchers
change Matcher interface to take start position
add helper funcs for common repetition, EOF matcher
implement Bytes and Runes matchers
implement EBNF alt/seq/repeat, tests
configure golangci-lint
refactor, test
fix printing ascii table when last char is allowed
linter: remove commented-out linter
implement ascii table for efficient lookup of allowed ascii chars
initial commit