BIG UPDATE: zsh: moved lots of things out of the zshrc

.config/shell/functions/mkcd

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# make a directory and cd into it
+mkcd() {
+   mkdir -p "$1" || error "$0" $LINENO
+   cd "$1" || error "$0" $LINENO
+}
+
+error() {
+   ERROR_CODE="$?"
+   >&2 echo "($1) An error occurred on line number $2"
+   return $ERROR_CODE
+}