feat: add cross-compilation support with --target flag

- Updated build and run commands to accept a --target option for specifying target platforms.
- Enhanced documentation to include cross-compilation usage and supported targets.
- Modified configuration to allow target-specific settings and toolchains.
- Introduced a new test command to run project tests with specified profiles and targets.
- Improved handling of target directories and output structure for different platforms.
- Added support for multiple targets in the configuration file.
- Implemented inheritance for workspace and dependencies based on target and profile.

src/core/builder/mod.rs

@@ -10,6 +10,8 @@ pub struct BuildContext<'a> {
     pub compiler: &'a str,
     pub language: &'a str,
     pub standard: &'a str,
+    #[allow(dead_code)]
+    pub target: Option<&'a str>,
     pub target_dir: Option<&'a str>,
     pub kind: &'a str,
     pub platform: Option<&'a str>,