A couple more small changes

Author: alecbcs

tutorial_environments.rst

@@ -199,7 +199,7 @@ So, adding specs to an environment at a later point in time will not cause exist
      `install-level build parallelism <https://spack.readthedocs.io/en/latest/packaging_guide.html#install-level-build-parallelism>`_.
 
 ^^^^^^^^^^^^^^
-Using packages
+Using Packages
 ^^^^^^^^^^^^^^
 
 Spack environments provide a convenient way to use your installed packages by automatically making them available in your shell environment.
@@ -307,10 +307,10 @@ The output shows the special ``spack.yaml`` configuration file that Spack uses t
 
 There are several important parts of this file:
 
-* ``specs:``: The list of package specs to install in the environment.
-* ``view:``: Controls whether the environment generates a *view* (the
+* ``specs:`` The list of package specs to install in the environment.
+* ``view:`` Controls whether the environment generates a *view* (the
   directory tree with symlinks to installed packages we discussed earlier).
-* ``concretizer:unify:``: Determines how package specs in the environment are
+* ``concretizer:unify:`` Determines how package specs in the environment are
   concretized together to reduce duplicated dependencies when possible.
 
 The ``specs`` list should look familiar -- these are the package specs we've been modifying previously with ``spack add`` and ``spack install``.
@@ -353,7 +353,9 @@ Change it to include the ``packages:mpi:require`` entry below:
          require: [mpich]
 
      # add package specs to the `specs` list
-     specs: [tcl, trilinos]
+     specs:
+     - tcl
+     - trilinos
 
 
 .. note::