New docs

docs/configuration/build-section.md

@@ -1,2 +1,31 @@
 # Build section
 
+## Schema
+
+```toml
+[build]
+language = "c"
+standard = "c11"
+compiler = "clang"
+kind = "bin"
+# optional:
+# target = "./dist"
+# cflags = ["-Wall"]
+# ldflags = ["-lm"]
+```
+
+## Fields
+
+- `language` (string, required): `c`, `c++`, `cpp`, or `cxx`.
+- `standard` (string, required): language standard passed to compiler.
+- `compiler` (string, required): compiler command (for example `clang`, `gcc`, `cl`).
+- `kind` (string, required): `bin` or `staticlib`.
+- `target` (string, optional): custom output directory for final artifact.
+- `cflags` (string array, optional): extra compile flags.
+- `ldflags` (string array, optional): extra link flags.
+
+## Behavior notes
+
+- Compiler backend is selected by compiler string (`gcc`, `clang`, `cl`, `clang-cl`).
+- Empty or unknown compiler value falls back to clang-like build path.
+- `run` is not allowed for `kind = "staticlib"`.