doc: add index for Lib

src/pylib/Lib/index.nim

@@ -0,0 +1,9 @@
+import ./private/doc_utils/genIndex
+##[
+# Lib
+
+Python standard libraries
+porting in nimpylib
+
+]##
+genIndexHere()

src/pylib/Lib/private/doc_utils/genIndex.nim

@@ -0,0 +1,25 @@
+
+import std/macros
+import std/strutils
+import std/os
+
+proc nimpylibLibFilter*(t: tuple[kind: PathComponent, path: string]): bool =
+  t.kind != pcDir and t.kind != pcLinkToDir and
+    t.path != "index.nim" and
+    not t.path.endsWith"_impl" and
+    not t.path.startsWith"n_"
+
+type PathFilter* = typeof nimpylibLibFilter  ## path is relative
+
+proc indexAsMdStr*(dir: string, filter=nimpylibLibFilter): string =
+  for t in dir.walkDir(relative=true):
+    if filter(t):
+      let
+        fn = t.path
+        libn = fn.changeFileExt("")
+        url = fn.changeFileExt("html")
+      result.add "- [$#]($#)\n".format(libn, url)
+
+
+macro genIndexHere*(filter: static[PathFilter] = nimpylibLibFilter) =
+  newCommentStmtNode indexAsMdStr(getProjectPath(), filter)