feat: add code testing

[heyAyushh]

Problem

This PR introduces testing for snippets imported in markdown using code-import.

Summary of Changes

• Seperated code files for cookbook wallet section
• setup pnpm workspace
• turborepo monorepo (in case code folder grows with multiple projects (react testing, mobile testing etc))
• added tests with node:test
• added GitHub Actions for testing only changed scripts on PR and all tests on schedule

Fixes #

• Bug in code-import where It failed when line ranges weren't mentioned

[ZYJLiu]

Can you double check the content displays correctly on solana-com. It looks like if you don't include a filename for a snippet, the provided file path gets used.

Also, why is there a file path, but the code block still contains the snippet?

```javascript file=/code/content/cookbook/wallets/create-keypair.ts#L1-L3
import { Keypair } from "@solana/web3.js";

const keypair = Keypair.generate();
```

[heyAyushh]

Code block has content for crowdin support i guess.

[heyAyushh]

This should be a PR on solana-com?

[ZYJLiu]

Can you provide more context on the changes and instructions for how I can test your changes locally? Please include the commands to run.
Is turbo supposed to be included as a dev dependency?

When I ran turbo test I got the following error:

turbo 2.2.3

• Packages in scope: solana-developer-content-api, solana-developer-content-code
• Running test in 2 packages
• Remote caching disabled
solana-developer-content-api:build: cache miss, executing 1cb178dcc001b143
solana-developer-content-code:test: cache miss, executing f6823e566d70ef4f
solana-developer-content-api:build: 
solana-developer-content-code:test: 
solana-developer-content-api:build: 
solana-developer-content-api:build: > [email protected] build /developer-content
solana-developer-content-api:build: > pnpm code-import && pnpm prettier:i18n && pnpm contentlayer:build && next build
solana-developer-content-api:build: 
solana-developer-content-code:test: 
solana-developer-content-code:test: > [email protected] test /developer-content/code
solana-developer-content-code:test: > node --import tsx --test '**/*.test.ts' --trace-deprecation
solana-developer-content-code:test: 
solana-developer-content-code:test: Could not find '/developer-content/code/**/*.test.ts'
solana-developer-content-code:test:  ELIFECYCLE  Test failed. See above for more details.
solana-developer-content-code:test: ERROR: command finished with error: command (/developer-content/code) /usr/local/bin/pnpm run test exited (1)
solana-developer-content-code#test: command (/developer-content/code) /usr/local/bin/pnpm run test exited (1)

 Tasks:    0 successful, 2 total
Cached:    0 cached, 2 total
  Time:    383ms 
Failed:    solana-developer-content-code#test

 ERROR  run failed: command  exited (1)

Also the following error if I run pnpm run test in the new /code folder.

> [email protected] test /developer-content/code
> node --import tsx --test '**/*.test.ts' --trace-deprecation

Could not find '/developer-content/code/**/*.test.ts'
 ELIFECYCLE  Test failed. See above for more details.
 ```

[heyAyushh]

Can you provide more context on the changes and instructions for how I can test your changes locally? Please include the commands to run. Is turbo supposed to be included as a dev dependency?

When I ran turbo test I got the following error:

turbo 2.2.3

• Packages in scope: solana-developer-content-api, solana-developer-content-code
• Running test in 2 packages
• Remote caching disabled
solana-developer-content-api:build: cache miss, executing 1cb178dcc001b143
solana-developer-content-code:test: cache miss, executing f6823e566d70ef4f
solana-developer-content-api:build: 
solana-developer-content-code:test: 
solana-developer-content-api:build: 
solana-developer-content-api:build: > [email protected] build /developer-content
solana-developer-content-api:build: > pnpm code-import && pnpm prettier:i18n && pnpm contentlayer:build && next build
solana-developer-content-api:build: 
solana-developer-content-code:test: 
solana-developer-content-code:test: > [email protected] test /developer-content/code
solana-developer-content-code:test: > node --import tsx --test '**/*.test.ts' --trace-deprecation
solana-developer-content-code:test: 
solana-developer-content-code:test: Could not find '/developer-content/code/**/*.test.ts'
solana-developer-content-code:test:  ELIFECYCLE  Test failed. See above for more details.
solana-developer-content-code:test: ERROR: command finished with error: command (/developer-content/code) /usr/local/bin/pnpm run test exited (1)
solana-developer-content-code#test: command (/developer-content/code) /usr/local/bin/pnpm run test exited (1)

 Tasks:    0 successful, 2 total
Cached:    0 cached, 2 total
  Time:    383ms 
Failed:    solana-developer-content-code#test

 ERROR  run failed: command  exited (1)

Also the following error if I run pnpm run test in the new /code folder.

> [email protected] test /developer-content/code
> node --import tsx --test '**/*.test.ts' --trace-deprecation

Could not find '/developer-content/code/**/*.test.ts'
 ELIFECYCLE  Test failed. See above for more details.
 ```

I added a testing section in Contibuting.md

   pnpm install
   cd code
   pnpm turbo test

let me know if this command doesn't work.

[heyAyushh]

This PR resolves the issue where code path was shown on the block as name.

solana-foundation/solana-com#96