Shell tools 101, sort command: Adds a sort by column example using the -k flag
Adhere change to the style guide with regards to line endings on each sentence
Merge branch 'master' of https://github.com/pedrodelgallego/curriculum into opsschool/master
style: update shell_tools to conform to style
shell_tools: style, updated code block indentations
shell_tools: updated ls for clearer reading and typos
shell_tools: cat, style and wording
shell_tools: cat, reference UUOC, fixes #118
shell_tools: add todo and note syntax notation
shell_tools: whitespace