feat: add bats tests, docs (#139)

* fix(test): ensure bats file list uses xargs

* docs(readme): use yarn for testing instructions

* fix(test): ensure pipelines fail properly

* docs(alias): fix table header

---------

Signed-off-by: Ismo Vuorinen <ismo@ivuorinen.net>

local/bin/fzf.md

@@ -0,0 +1,16 @@
+# fzf
+
+Binary of the fuzzy finder [fzf](https://github.com/junegunn/fzf).
+Use `fzf` as you would normally; this wrapper ships the prebuilt
+binary in the dotfiles.
+
+## Usage
+
+```bash
+fzf [options]
+```
+
+Refer to the upstream `fzf` documentation for all available
+flags and features.
+
+<!-- vim: set ft=markdown spell spelllang=en_us cc=80 : -->