refactor: move templates from root to share/spack

- This complies with the unix directory hierarchy standard (which Spack
  attempts to follow)
- Also unclutters the repo root directory.

etc/spack/defaults/config.yaml

@@ -21,7 +21,7 @@ config:
 
   # Locations where templates should be found
   template_dirs:
-    - $spack/templates
+    - $spack/share/spack/templates
 
 
   # default directory layout

lib/spack/docs/module_file_support.rst

@@ -290,15 +290,15 @@ installation of a package. The table below summarizes the essential
 information associated with the different file formats
 that can be generated by Spack:
 
-  +-----------------------------+--------------------+-------------------------------+----------------------------------+----------------------+
+  +-----------------------------+--------------------+-------------------------------+----------------------------------------------+----------------------+
   |                             | **Hook name**      |  **Default root directory**   | **Default template file**                    | **Compatible tools** |
-  +=============================+====================+===============================+==================================+======================+
+  +=============================+====================+===============================+==============================================+======================+
-  |  **Dotkit**                 | ``dotkit``         |  share/spack/dotkit           | templates/modules/modulefile.dk  | DotKit               |
+  |  **Dotkit**                 | ``dotkit``         |  share/spack/dotkit           | share/spack/templates/modules/modulefile.dk  | DotKit               |
-  +-----------------------------+--------------------+-------------------------------+----------------------------------+----------------------+
+  +-----------------------------+--------------------+-------------------------------+----------------------------------------------+----------------------+
-  |  **TCL - Non-Hierarchical** | ``tcl``            |  share/spack/modules          | templates/modules/modulefile.tcl | Env. Modules/LMod    |
+  |  **TCL - Non-Hierarchical** | ``tcl``            |  share/spack/modules          | share/spack/templates/modules/modulefile.tcl | Env. Modules/LMod    |
-  +-----------------------------+--------------------+-------------------------------+----------------------------------+----------------------+
+  +-----------------------------+--------------------+-------------------------------+----------------------------------------------+----------------------+
-  |  **Lua - Hierarchical**     | ``lmod``           |  share/spack/lmod             | templates/modules/modulefile.lua | LMod                 |
+  |  **Lua - Hierarchical**     | ``lmod``           |  share/spack/lmod             | share/spack/templates/modules/modulefile.lua | LMod                 |
-  +-----------------------------+--------------------+-------------------------------+----------------------------------+----------------------+
+  +-----------------------------+--------------------+-------------------------------+----------------------------------------------+----------------------+
 
 
 Spack ships with sensible defaults for the generation of module files, but

lib/spack/docs/tutorial_modules.rst

@@ -1385,11 +1385,12 @@ Module file templates
 ^^^^^^^^^^^^^^^^^^^^^
 
 The templates that Spack uses to generate module files are stored in the
-``templates/module`` directory, and they all share the same common structure.
+``share/spack/templates/module`` directory within the Spack prefix, and
-Usually, they start with a header that identifies the type of
+they all share the same common structure.  Usually, they start with a
-module being generated. In the case of hierarchical module files it's:
+header that identifies the type of module being generated. In the case of
+hierarchical module files it's:
 
-.. literalinclude:: ../../../templates/modules/modulefile.lua
+.. literalinclude:: ../../../share/spack/templates/modules/modulefile.lua
   :language: jinja
   :lines: 1-6
 
@@ -1403,7 +1404,7 @@ that can be overridden or extended by users, if need be.
 , delimited by ``{% ... %}``,
 are also permitted in the template language:
 
-.. literalinclude:: ../../../templates/modules/modulefile.lua
+.. literalinclude:: ../../../share/spack/templates/modules/modulefile.lua
   :language: jinja
   :lines: 73-88
 

lib/spack/spack/test/data/config.yaml

@@ -1,7 +1,7 @@
 config:
   install_tree: $spack/opt/spack
   template_dirs:
-  - $spack/templates
+  - $spack/share/spack/templates
   - $spack/lib/spack/spack/test/data/templates
   - $spack/lib/spack/spack/test/data/templates_again
   build_stage: