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/x-load-configs.md

@@ -0,0 +1,21 @@
+# x-load-configs
+
+Source shell configuration files for aliases and exports. Intended to
+be run after `dfm install` or when switching hosts.
+
+## Usage
+
+```bash
+x-load-configs
+```
+
+Set `VERBOSE=1` to print each file as it is sourced. Use `DEBUG=1` to
+enable tracing.
+
+### Example
+
+```bash
+VERBOSE=1 x-load-configs
+```
+
+<!-- vim: set ft=markdown spell spelllang=en_us cc=80 : -->