Documentation staticRead maximum file size limits (#13485)

lib/system.nim

@@ -2525,6 +2525,9 @@ proc staticRead*(filename: string): string {.magic: "Slurp".}
   ## Compile-time `readFile <io.html#readFile,string>`_ proc for easy
   ## `resource`:idx: embedding:
   ##
+  ## The maximum file size limit that ``staticRead`` and ``slurp`` can read is
+  ## near or equal to the *free* memory of the device you are using to compile.
+  ##
   ## .. code-block:: Nim
   ##     const myResource = staticRead"mydatafile.bin"
   ##