fix block spelling

README.org

@@ -7,13 +7,13 @@ example. For local (user) installation the local path must be in the
 Typically =$HOME/.local/lib/pythonX.Y/site-packages=
 
 Use either:
-#+BEGIN_SCR shell
+#+BEGIN_SRC shell
 pip install -e .
 pip install --user -e .
 python -m pip install -e .
 easy_install --prefix=$HOME/.local -e .
 pip install --install-option="--prefix-$HOME/.local" -e .
-#+END_SCR
+#+END_SRC
 
 * Uninstall
 pip uninstall materials