[Org files] remove python code for tangling, updated shebang

This commit removes all python source blocks that were previously used
to generate code. Consequently, the commands for tangling my org files
in the bootstrap script were updated.

[Bootstrap] A shebang header has been added to the org file, removing
the necessity of the shebang code block and manually setting
permissions for the script each time it is tangled.

org/config/spacemacs.org

@@ -2825,8 +2825,7 @@
    #+END_SRC
 
    Now, all keybindings that will be  defined can be invoked in Normal-mode with
-   the  src_emacs-lisp[:exports  results]{(princ  dotspacemacs-leader-key)}  key
-   followed by the sequence assigned to each keybinding.
+   the ~SPC~ key followed by the sequence assigned to each keybinding.
 
    Before some more specialized categories, I  have two commands which don’t fit
    into any other category  that I sometime use. The first one is  a fix for the