message: define tpl further up
diff: @@ -10,9 +10,9 @@ Third-party Libraries
  *********************
  Axom dependencies are grouped into four categories: Git submodules,
  -built-in TPLs in the Axom source tree, system-level TPLs, and other
  -TPL libraries. The following sections describe how to install and update
  -these dependencies for Axom.
  +built-in Third-party Libraries (TPLs) in the Axom source tree, system-level
  +TPLs, and other TPL libraries. The following sections describe how to
  +install and update these dependencies for Axom.
  * How does one add a new compiler or platform to the mix?
  * How does one build a new set of TPLs for a single platform or compiler
  