fix(docs): fix broken link and correct typos in HACKING.md and cache/README.md

[gajeshbhat]

Done

• Fixed typo "the your" → "your" in HACKING.md (line 23)
• Fixed typo "you" → "your" in HACKING.md (line 69)
• Fixed typo "promt" → "prompt" in cache/README.md (line 15)
• Fixed broken link to Launchpad Credentials creation script in Hacking.md. (screenshots attached below)

How to QA

• Open HACKING.md and verify line 23 reads: "Update your .env.local file with your secrets:" and also hover over the Download this script link and see the .py extension missing.
• Verify line 69 reads: "Create or update your .env.local file:"
• Open cache/README.md and verify line 15 reads: "To exit the interactive prompt, run"

Testing

• No testing required (explain why): Documentation-only changes, no code affected

Issue / Card

Fixes # (N/A - documentation fix)

Screenshots

[webteam-app]

gajeshbhat is not a collaborator of the repo

[gajeshbhat]

@steverydz This is short typo and incorrect link fix PR. Kindly give it a review if time permits.