[Doc] Update `grants.md` references

[emmanuel-ferdman]

Changes

Commit fixes all the broken references in grants.md.

Tests

• [x] make test run locally
• [x] relevant change in docs/ folder
• [ ] covered with integration tests in internal/acceptance
• [ ] relevant acceptance tests are passing
• [ ] using Go SDK

[github-actions[bot]]

If integration tests don't run automatically, an authorized user can run them manually by following the instructions below:

Trigger: go/deco-tests-run/terraform

Inputs:

• PR number: 4246
• Commit SHA: 01fa9412ace0788cb207a046c64d17165400bb3f

Checks will be approved automatically on success.

[eng-dev-ecosystem-bot]

Test Details: go/deco-tests/11916268801