1. BUILD_ON_LINUX.md is instruction of building Linux version
2. Update toml files in scripts/makefile/ and /Makefile.toml to support Linux
Building Windows/Linux release version is verified
Didn't get chance to verify building macos version
1. scripts\flowy-tool\Cargo.toml
- Remove shell dependency which does not support windows
2. scripts\makefile\env.toml
- Enhance environment checking for building app on windows
3. scripts\flowy-tool\src\util\file.rs
- Trim unnecessary prefix "\\?\" for std::fs::canonicalize(root) on windows
4. scripts\makefile\flutter.toml
- add dependency for "tasks.appflowy-windows" to copy dart_ffi.dll from rust build folder to flutter build folder
5. scripts\flowy-tool\src\proto\proto_gen.rs
- Remove dir by using platform independent code rather than calling *nix shell command
6. scripts\makefile\protobuf.toml
- tasks.gen_dart_event: call duckscript to gen_dart_event on windows platform
