Fix warnings

doc/limitations.rst

@@ -51,6 +51,7 @@ By default Leon assumes that unbounded data types can
 be arbitrarily large and that all well-founded recursive
 functions have enough stack space to finish their computation.
 Thus a verified program may crash at run-time due to:
+
   * stack overflow
   * heap overflow
 

doc/options.rst

@@ -14,7 +14,7 @@ you can do it by using a single dash ``-``. For example, ``-Ybrowse:typer``.
 The rest of this section presents all command-line options that Leon recognizes.
 
 Choosing which Leon feature to use
----------------------------
+----------------------------------
 
 The first group of options determine which feature of Leon will be used.
 These options are mutually exclusive. By default, ``--verify`` is chosen.