Update README Base links

[haileymarshall]

Summary:

• Updates README links that still pointed to the old base-org GitHub organization.
• Points the contract deployment and badge references to the current base organization.

Testing:

• Ran git diff --check.
• No build was run because this is a README-only documentation change.

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 1 Sum 2