add missing link

[ruhil6789]

Problem: The starter templates page (/starter-templates) returned 404, and the "Setup on Frameworks" section linked to non-existent routes (/getting-started/frameworks, /getting-started/frameworks/nextjs, /getting-started/frameworks/svelte), causing 404s for users.
Solution:
Starter templates page – Added a /starter-templates page that lists Mesh starter templates (Next.js, Svelte, Aiken, Midnight, Minting, Standalone) with links to GitHub repos and live demos where available, and added a "Starter Templates" card to the Resources section.
Framework links – Updated framework links in links-frameworks.ts to point to existing routes: /resources/platforms, /resources/platforms/nextjs, and /svelte/getting-started.
Turbo dev – Bumped the root dev script concurrency from 15 to 16 so it meets Turbo’s requirement for the number of persistent tasks.
Affect components

Please indicate which part of the Mesh Repo
[ ] @meshsdk/common
[ ] @meshsdk/contract
[ ] @meshsdk/core
[ ] @meshsdk/core-csl
[ ] @meshsdk/core-cst
[ ] @meshsdk/hydra
[ ] @meshsdk/provider
[ ] @meshsdk/react
[ ] @meshsdk/svelte
[ ] @meshsdk/transaction
[ ] @meshsdk/wallet
[x] Mesh playground (i.e. https://meshjs.dev/)
[ ] Mesh CLI
Type of Change
Please mark the relevant option(s) for your pull request:
[x] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
[x] Bug fix (non-breaking change which fixes an issue)
[ ] Code refactoring (improving code quality without changing its behavior)
[ ] Documentation update (adding or updating documentation related to the project)
Related Issues
N/A
Checklist
Please ensure that your pull request meets the following criteria:
[x] My code is appropriately commented and includes relevant documentation, if necessary
[ ] I have added tests to cover my changes, if necessary
[x] I have updated the documentation, if necessary
[ ] All new and existing tests pass (i.e. npm run test)
[ ] The build is pass (i.e. npm run build)
Additional Information
Starter templates and their GitHub links are based on: https://github.com/MeshJS?q=template&type=all&language=&sort=
Live demo URLs use the existing pattern (e.g. aiken-template.meshjs.dev, starter-template.meshjs.dev). Any template’s live URL can be updated in apps/playground/src/data/links-starter-templates.ts if needed.