chore: Add pre-commit/pygrep-hooks to pre-commit hooks (#2382)

* Impliment repo-review PC170: Uses PyGrep hooks (only needed if RST present).
   - c.f. https://learn.scientific-python.org/development/guides/style/#PC170

Author: matthewfeickert

.pre-commit-config.yaml

@@ -27,6 +27,13 @@ repos:
       # exclude generated files
       exclude: ^validation/|\.dtd$|\.xml$
 
+- repo: https://github.com/pre-commit/pygrep-hooks
+  rev: "v1.10.0"
+  hooks:
+    - id: rst-backticks
+    - id: rst-directive-colons
+    - id: rst-inline-touching-normal
+
 - repo: https://github.com/astral-sh/ruff-pre-commit
   rev: "v0.1.4"
   hooks:

docs/index.rst

@@ -1,7 +1,7 @@
 .. pyhf documentation master file, created by
    sphinx-quickstart on Fri Feb  9 11:58:49 2018.
    You can adapt this file completely to your liking, but it should at least
-   contain the root `toctree` directive.
+   contain the root ``toctree`` directive.
 
 .. toctree::
    :hidden: