chore: add feature to build documentation

build.zig

@@ -46,4 +46,14 @@ pub fn build(b: *std.Build) void {
     // This will evaluate the `test` step rather than the default, which is "install".
     const test_step = b.step("test", "Run library tests");
     test_step.dependOn(&run_main_tests.step);
+
+    // Build Documentation
+    const doc = b.addInstallDirectory(.{
+        .source_dir = lib.getEmittedDocs(),
+        .install_dir = .prefix,
+        .install_subdir = "docs",
+    });
+
+    const doc_step = b.step("doc", "Generate documentation");
+    doc_step.dependOn(&doc.step);
 }