Updates docs, bumps to v0.4.0

Adds support for :show_dirs? option to ls/2 function

Clarifies docs for ls/2 :filter option

Properly adds Regex line filtering for grep/2

Adds support for simple strings to be used in ls filter

Clarifies docs

Updates grep_rl so its options are routed thru to ls/2; updates docs

Adds head/2 and tail/2, bumps to v0.3.0

Replaces Stream.flat_map with Stream.filter to simplify several functions

Updates docs

Adds support for arity 1 function as grep pattern; bumps to version 0.2.0

Adds functions for line_count/1, grep/2, and grep_rl/3

Fixes license reference

Fixes logo

Fixes logo