examples: add a pandera interoperability recipe (validate + repair)

[JohnnyWilson16]

Problem

The docs contrast freshdata with Great Expectations, ydata-profiling, and sweetviz, and recipes exist or are requested for those tools (#7, #8, #9). But pandera — one of the most common pandas schema-validation libraries — is never mentioned, and there's no recipe showing how the two fit together.

Expected outcome

A short, runnable recipe showing pandera validating a schema while freshdata repairs the data — framed as complementary (validate vs. repair), the same framing used for Great Expectations.

Relevant files

• New examples/pandera_recipe.py
• An entry in examples/README.md
• Optionally a short paragraph in docs/faq.md

Acceptance criteria

• The script runs top-to-bottom on a small inline DataFrame with no external data.
• It shows a pandera schema check before and/or after fd.clean(df).
• The example is indexed in examples/README.md.

Difficulty / skills

good first issue — Python, pandas, basic pandera. Great first PR; see CONTRIBUTING.md and the contributor roadmap.