chore: include pre-built dist for github install

dist/tools/ast-grep/downloader.d.ts

@@ -0,0 +1,5 @@
+export declare function getCacheDir(): string;
+export declare function getBinaryName(): string;
+export declare function getCachedBinaryPath(): string | null;
+export declare function downloadAstGrep(version?: string): Promise<string | null>;
+export declare function ensureAstGrepBinary(): Promise<string | null>;