A few rst doc fixes (#17151)

* Fix a couple of rst formatting issues

* no need for the extra space

lib/pure/strutils.nim

@@ -2205,7 +2205,7 @@ func escape*(s: string, prefix = "\"", suffix = "\""): string {.rtl,
   ##
   ## See also:
   ## * `unescape func<#unescape,string,string,string>`_ for the opposite
-  ## operation
+  ##   operation
   result = newStringOfCap(s.len + s.len shr 2)
   result.add(prefix)
   for c in items(s):

lib/system/memalloc.nim

@@ -213,7 +213,7 @@ when hasAlloc and not defined(js):
     ## to it is undefined behaviour!
     ##
     ## See also:
-    ## `allocShared0 <#allocShared0.t,Natural>`_.
+    ## * `allocShared0 <#allocShared0.t,Natural>`_.
     incStat(allocCount)
     allocSharedImpl(size)