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>

scripts/install-z.md

@@ -0,0 +1,11 @@
+# install-z
+
+Installs [z](https://github.com/rupa/z), a directory jumping tool.
+
+## Usage
+
+```bash
+scripts/install-z.sh
+```
+
+Once installed add `. ~/.z` to your shell startup file to enable the command.