New docs

docs/getting-started/project-structure.md

@@ -1,2 +1,39 @@
 # Project structure
 
+## Minimal project
+
+```text
+project/
+- dcr.toml
+- src/
+- - main.c
+```
+
+## Typical generated/optional files
+
+```text
+project/
+- dcr.toml
+- dcr.lock
+- src/
+- - ... source files ...
+- target/
+- - debug/
+- - - obj/
+- - - deps/
+- - release/
+- - - obj/
+- - - deps/
+```
+
+## Meaning
+
+- `dcr.toml`: main project configuration.
+- `dcr.lock`: generated lock file for resolved path dependencies.
+- `src/`: recursively scanned source directory.
+- `target/<profile>/obj/`: cached object files for incremental rebuild.
+- `target/<profile>/deps/`: synchronized copies of path dependencies.
+- `target/<profile>/<name>` (or `.exe` on Windows): output for `kind = "bin"`.
+- `target/<profile>/lib<name>.a` (or `<name>.lib` on Windows): output for `kind = "staticlib"`.
+
+If `build.target` is set, the final artifact is written to that custom directory, while object cache still stays in `target/<profile>/obj`.