shellcheck metadata update and shebangs and such

.bashrc

@@ -1,4 +1,5 @@
-#!/bin/bash
+#!/usr/bin/env bash
+# shellcheck disable=SC1090,SC1091
 #
 # ~/.bashrc
 #

.xinitrc

@@ -1,4 +1,6 @@
-#!/bin/bash
+#!/usr/bin/env bash
+# shellcheck disable=SC1090,SC1091
+
 # load system xinit scripts
 if [ -d /etc/X11/xinit/xinitrc.d ]; then
 	for f in "/etc/X11/xinit/xinitrc.d"/?*.sh; do