Revert changes to fix warning about hardcoded link

The warning is overaggressive: 
sphinx-doc/sphinx#10112 and RST does not 
support nesting of directives/prefixes so we cannot use both 
:bdg-link-primary: and :nwb_extension_git:

docs/source/core_tools/core_tools_home.rst

@@ -67,7 +67,7 @@ Neurodata Extensions (NDX) are used to extend the NWB data standard, e.g., to in
 
 **NDX Template**
 
- The :ndx-template-docs:`NDX Template <>`  provides a template for creating Neurodata Extensions (NDX) for the NWB data standard. :bdg-link-primary:`Source <nwb_extension_git:ndx-template>`
+ The :ndx-template-docs:`NDX Template <>`  provides a template for creating Neurodata Extensions (NDX) for the NWB data standard. :bdg-link-primary:`Source <https://github.com/nwb-extensions/ndx-template>`
 
  When creating a new extension, the NDX-template will create a detailed NEXTSTEPS.md file describing how to create an extension and how to submit it to the NDX catalog.
 
@@ -77,7 +77,7 @@ Neurodata Extensions (NDX) are used to extend the NWB data standard, e.g., to in
 
 **Publishing NDX**
 
- The :nwb_extension_git:`staged-extensions` GitHub repository is used to register new extensions for publication in the :ndx-catalog:`Neurodata Extensions Catalog (NDX Catalog) <>`. :bdg-link-primary:`Source <nwb_extension_git:staged-extensions>`
+ The :nwb_extension_git:`staged-extensions` GitHub repository is used to register new extensions for publication in the :ndx-catalog:`Neurodata Extensions Catalog (NDX Catalog) <>`. :bdg-link-primary:`Source <https://github.com/nwb-extensions/staged-extensions>`
 
 **Documentation Utilities**