doc: update the readme.md

[kerthcet]

What this PR does / why we need it

Which issue(s) this PR fixes

Fixes #

Special notes for your reviewer

Does this PR introduce a user-facing change?

[kerthcet]

/lgtm
/kind documentation

[Copilot]

🟡 Changes recommended

Adds behavioral validation without corresponding tests and the PR metadata currently frames it as documentation-only.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Updates Nebula documentation to better describe capabilities and configuration while tightening provider catalog CSV validation to prevent invalid pricing data from entering the system.

Changes:

• Add a README “Features” section and document NodePool spec.egress configuration in the example.
• Reject negative price_per_hour values when parsing provider offering CSVs (in addition to non-finite values).

File summaries

File	Description
README.md	Adds a Features section and expands the NodePool example to include spec.egress.
pkg/provider/catalog/catalog.go	Extends CSV price validation to reject negative values with a clearer error message.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 3
• Review effort level: Lite

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[Copilot]

🟡 Changes recommended

It introduces a behavior change (reject negative prices) without corresponding test coverage, and adds a doc TOC entry that links to a missing section.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

Suppressed comments (1)

pkg/provider/catalog/catalog.go:196

• This change now rejects negative prices, but the existing tests only cover non-finite values (see TestLoadFrom_RejectsNonFinitePrice). Please add a test case that ensures a negative price_per_hour (e.g. "-1") is rejected, so this behavior stays protected.

		if math.IsNaN(price) || math.IsInf(price, 0) || price < 0 {
			return nil, fmt.Errorf("row %d: price_per_hour %q must be a non-negative finite number", i, field(rec, colPrice))

• Files reviewed: 3/3 changed files
• Comments generated: 1
• Review effort level: Lite

[kerthcet]

/hold

[kerthcet]

/unhold

[kerthcet]

/lgtm

[Copilot]

🔵 Needs a closer look

The PR scope/title is doc-only but includes functional code changes, and the new negative-price behavior should be covered by a unit test.

Review details

Suppressed comments (2)

pkg/provider/catalog/catalog.go:196

• The new validation also rejects negative prices, but the unit tests only cover non-finite values (NaN/Inf). Add a test case for a negative price_per_hour (e.g. "-0.01") to ensure this behavior stays covered.

		if math.IsNaN(price) || math.IsInf(price, 0) || price < 0 {
			return nil, fmt.Errorf("row %d: price_per_hour %q must be a non-negative finite number", i, field(rec, colPrice))

pkg/provider/catalog/catalog.go:196

• This PR is titled/positioned as a README-only doc update, but it also changes CSV parsing/validation behavior in code. Please update the PR title/description to reflect the code change (or split the code fix into a separate PR) so reviewers can triage scope correctly.

		if math.IsNaN(price) || math.IsInf(price, 0) || price < 0 {
			return nil, fmt.Errorf("row %d: price_per_hour %q must be a non-negative finite number", i, field(rec, colPrice))

• Files reviewed: 2/2 changed files
• Comments generated: 0 new
• Review effort level: Lite

[InftyAI-Agent]

Approved: PR has both lgtm and approved labels