Expose some layouter elements, improve readme (#12361)

Useful for writing linters and static code analysis

compiler/layouter.nim

@@ -21,7 +21,7 @@ type
   SemicolonKind = enum
     detectSemicolonKind, useSemicolon, dontTouch
 
-  LayoutToken = enum
+  LayoutToken* = enum
     ltSpaces,
     ltCrucialNewline, ## a semantically crucial newline (indentation!)
     ltSplittingNewline, ## newline used for splitting up long
@@ -41,8 +41,8 @@ type
     col, lastLineNumber, lineSpan, indentLevel, indWidth*, inSection: int
     keepIndents*: int
     doIndentMore*: int
-    kinds: seq[LayoutToken]
-    tokens: seq[string]
+    kinds*: seq[LayoutToken]
+    tokens*: seq[string]
     indentStack: seq[int]
     fixedUntil: int # marks where we must not go in the content
     altSplitPos: array[SplitKind, int] # alternative split positions

compiler/readme.txt

@@ -2,3 +2,4 @@ This directory contains the Nim compiler written in Nim. Note that this
 code has been translated from a bootstrapping version written in Pascal, so
 the code is **not** a poster child of good Nim code.
 
+See https://nim-lang.org/docs/intern.html for more information.