Add data feeds starter kit example

[thodges-gh]

Description

Adds a Data Feeds starter-kit template to the chainlink-data-feeds-skill so the agent
can scaffold a complete, working Foundry project on request. The template — adapted from
the Foundry starter kit — lives
under chainlink-data-feeds-skill/templates/starter-kit/ and includes:

• src/PriceFeedConsumer.sol — a price feed consumer contract using
  AggregatorV3Interface
• script/PriceFeedConsumer.s.sol — a Foundry deployment script
• test/PriceFeedConsumer.t.sol with test/mocks/MockV3Aggregator.sol — tests and a mock
  aggregator
• foundry.toml, remappings.txt, and README.md — project config and setup docs

SKILL.md is updated to point the agent at this template when a user asks for a working
example, and its metadata.version is bumped to 0.0.4.

Justification

Developers frequently want a ready-to-run example rather than isolated snippets. Bundling
a known-good Foundry project lets the skill scaffold a functional Data Feeds project
end-to-end (build, test, deploy) instead of assembling files piecemeal, improving the
out-of-the-box experience and reducing integration errors.

Testing: Ensure you're on skill version 0.0.4, then in an empty project ask the
agent: "Give me a working example of a data feeds project." The agent should use the
templates/starter-kit code to scaffold a functional Foundry project.

[thodges-gh]

My test results:

Project	Artifact	forge test	Gate B	Correct.	Complete.	Fidelity	Safety	Fresh.	Overall	Grade
claude-opus-4.8-high	yes	4/4 out of the box	PASS	100	100	100	100	100	100.0	A+
gemini-3.1-pro-preview	yes	4/4 out of the box	PASS	100	95	100	100	90	97.8	A+
codex-gpt-5.5-medium	yes (no lib/)	4/4 after forge install	PASS	100	88	100	100	100	97.0	A+
codex-gpt-5.5-xhigh	yes (no lib/)	4/4 after forge install	PASS	100	88	100	100	100	97.0	A+
claude-opus-4.8-medium	yes	4/4 out of the box	PASS	100	85	100	100	90	95.3	A
claude-opus-4.8-xhigh	yes	4/4 out of the box	PASS	100	85	100	100	90	95.3	A
claude-sonnet-4.6-high	yes	4/4 out of the box	PASS	100	85	100	100	90	95.3	A
claude-sonnet-4.6-xhigh	yes	4/4 out of the box	PASS	100	85	100	100	90	95.3	A
codex-gpt-5.5-low	yes (no lib/, nested)	4/4 after forge install	PASS	100	83	95	100	100	94.8	A
gemini-3-flash-preview	yes	4/4 out of the box	PASS	100	85	95	100	90	94.3	A
claude-opus-4.8-low	yes (nested)	4/4 out of the box	PASS	100	80	100	100	90	94.0	A
codex-gpt-5.5-high	yes (no lib/)	4/4 after forge install	PASS	100	88	85	100	100	94.0	A
claude-sonnet-4.6-low	no (chat only)	none on disk	Gate A fail	0	0	0	n/a	n/a	12.0	F
claude-sonnet-4.6-medium	no (chat only)	none on disk	Gate A fail	0	0	0	n/a	n/a	12.0	F

Notes: "out of the box" means forge test is green with the repository exactly as delivered (dependencies vendored
under lib/). "after forge install" means the source is correct and tests pass once the dependencies its README
documents are installed; the codex runs do not commit lib/, which matches the starter-kit template's own packaging
(the template ships no lib/ either and tells the user to forge install).