message: clarify section header
diff: @@ -87,14 +87,15 @@ instructions on how to update a built-in TPL are as follows:
  #. Follow the normal pull request work flow. More info on :ref:`pullrequest-label`.
  -TPLs (system-level and external libraries)
  -------------------------------------------
  +Shared Third-party Library Installation Steps
  +---------------------------------------------
  The following instructions describe how to install local copies of Axom
  -TPLs on Livermore Computing (LC) platforms. Typically, this process is
  -followed when you want to build and test Axom against new versions of TPLs
  -to make sure everything works properly before deploying a new TPL set for
  -other Axom developers to use during development, to use in Axom Gitlab CI testing, etc.
  +TPLs on Livermore Computing (LC) platforms and recreate our Docker containers
  +with a new set of TPLs. Typically, this process is followed when you want to
  +update one or more TPLs which Axom depends on. After they are built and
  +the required changes are merged into develop, they will be available for
  +other Axom developers to use during development, in Axom Gitlab CI testing, etc.
  #. **Working on a local branch.**
  Make a local clone of the Axom repo and create a branch to work on. Working
  