contrib: rename no-op-example to barebones-example

"no-op" might suggest that it doesn't do anything, when in reality it
does exactly what filter-repo does.  Rename it to barebones-example.

Signed-off-by: Elijah Newren <newren@gmail.com>

contrib/filter-repo-demos/README.md

@@ -9,7 +9,7 @@ that could be done.
 
 Command                         |Description
 -------|-----------
-no-op-example        |Simple example with no modifications to filter-repo behavior, just showing what to import and run.
+barebones-example    |Simple example with no modifications to filter-repo behavior, just showing what to import and run.
 insert-beginning     |Add a new file (e.g. LICENSE/COPYING) to the beginning of history.
 signed-off-by        |Add a Signed-off-by tag to a range of commits
 lint-history         |Run some lint command on all non-binary files in history.

contrib/filter-repo-demos/barebones-example

@@ -1,8 +1,8 @@
 #!/usr/bin/env python3
 
 """
-This is a simple program that just behaves identically to git-filter-repo.
-Its entire purpose is just to show what to import and run to get the normal
+This is a simple program that behaves identically to git-filter-repo.  Its
+entire purpose is just to show what to import and run to get the normal
 git-filter-repo behavior, to serve as a starting point for you to figure
 out what you want to modify.
 """