switch to using shell builtins for thought rendering

www/src/scripts/builtins/execute-bash/execute_bash.py

@@ -0,0 +1,11 @@
+def _execute_bash(*args):
+    from re import sub
+    from os import environ as hy_env
+    from subprocess import check_output
+    env = hy_env
+    env['PATH'] = hy_env['PATH'] + ':./scripts'
+    path = args[0]
+    with open(path, 'r') as fp:
+        _hy_anon_var_1 = fp.read()
+    print(sub('\\$\\[(.*?)\\]', lambda sequence: check_output(sequence.group(1), shell=True, executable='/bin/bash', env=env).decode().strip(), _hy_anon_var_1))
+    return 0