Small org tweaks

The `org-adapt-indentation` should probably not be set as the new default is
probably a better default. But I have a lot of org files that might break due
to this change.

init.org

@@ -1149,8 +1149,18 @@
    #+BEGIN_SRC emacs-lisp
    (require 'org)
    (add-to-list 'org-file-apps '("\\.pdf\\'" . emacs))
+   (setq org-adapt-indentation t)
    #+END_SRC
 
+   #+begin_src emacs-lisp
+   (setq org-babel-python-command "python3")
+   (org-babel-do-load-languages
+    'org-babel-load-languages
+    '((emacs-lisp . t)
+      (python . t)
+      (clojure . t)))
+   #+end_src
+
 ** Haskell
 
  =haskell-doc-mode= is similar to =eldoc=, it displays documentation in