chore: move cpp folder into packages/core

[graszka22]

What/Why?

Moves packages/react-native-enriched-markdown/cpp into packages/core. packages/core will be the source of truth for cpp core and used by other packages.

There is a hack in CmakeLists.txt and ReactNativeEnrichedMarkdown.podspec‎:

• in dev we use files from package/core, on ios the package/core is a pod (no need to publish it anywhere) and on android we use a relative path
• in release we use files copied from package/core to packages/react-native-enriched-markdown/cpp. The prepack script copies them automatically before packing the npm package.

I don't like it but I see no other easy way, because cocoapods doesn't follow symlinks and doesn't allow sources from outside packages/react-native-enriched-markdown. And cmake has issues with following symlinks too. I think the only other solution would be publishing the core separately but we'd rather avoid this?

After react-native-enriched-markdown will depend on the native libraries the release flow will change anyway and probably will be nicer.

Testing

• Built the example apps.
• Created a tarball and added a dependency on the tarball in the example app. The tarball contained cpp code. Built the app and it worked.

PR Checklist

• Code compiles and runs on iOS
• Code compiles and runs on Android
• Updated documentation/README if applicable
• Ran example app to verify changes
• E2E tests are passing
• Required E2E tests have been added (if applicable)

[hryhoriiK97]

LGTM! I've tested this locally - I generated a .tgz file and installed it in a newly created RN project - everything works as before. Also, I've left a few comments — please take a look at them 🙏

[hryhoriiK97]

This hardcodes the iOS minimum to 15.1, while ReactNativeEnrichedMarkdown.podspec uses the dynamic min_ios_version_supported from React Native. If the RN minimum changes, these will drift apart and could cause CocoaPods resolution issues. Let's use the same helper here

[hryhoriiK97]

The first two assignments to s.private_header_files and s.source_files are immediately overridden in the unless branch - they only matter for the else (monorepo) path. This reads a bit confusingly. Would be clearer as a straight if/else. What do you think about this?

if monorepo
  s.private_header_files = "ios/**/*.h"
  s.source_files = "ios/**/*.{h,m,mm,cpp,swift}"
  s.dependency "EnrichedMarkdownCore"
else
  s.private_header_files = "ios/**/*.h", "cpp/**/*.{h,hpp}"
  s.source_files = "ios/**/*.{h,m,mm,cpp,swift}", "cpp/md4c/*.{c,h}", "cpp/parser/*.{hpp,cpp}"
end

[hryhoriiK97]

Nit: the path goes up to the repo root and back down. Since we're already in packages/react-native-enriched-markdown, this is equivalent and shorter:

"build:wasm": "bash ../core/cpp/wasm/build.sh",