v3.3.0 (#525)

* feat: directory-scoped cheatpaths

`cheat` now searches for a `.cheat` directory in the current working
directory. If found, that directory is (temporarily) appended to the slice
of cheatpaths.

* makefile wip

* fix: appeases linter

Appeases linter (`go vet`) by adding quotation marks to YAML struct
tags.

* chore: modifies .gitignore

Adds `tag` to `.gitignore`

* feat: adds Makefile

Adds a `Makefile` for managing build-related tasks.

* chore: documents directory-local paths

Adds documentation regarding the new directory-local cheatpath
functionality.

* chore: updates dependencies

* chore: bumps version to 3.3.0

* chore: updates bin scripts

- Removes `build_release.sh`
- Places deprecation notice in `build_devel.sh`, as its purpose has been
  superceded by the `Makefile`.

README.md

@@ -125,6 +125,11 @@ If a user attempts to edit a cheatsheet on a read-only cheatpath, `cheat` will
 transparently copy that sheet to a writeable directory before opening it for
 editing.
 
+### Directory-scoped Cheatpaths ###
+At times, it can be useful to closely associate cheatsheets with a directory on
+your filesystem. `cheat` facilitates this by searching for a `.cheat` folder in
+the current working directory. If found, the `.cheat` directory will
+(temporarily) be added to the cheatpaths.
 
 Usage
 -----