org: add syntax highlighting for three HOA examples

* doc/org/concepts.org, doc/org/ltl2tgba.org, doc/org/ltldo.org: Here.

doc/org/concepts.org

@@ -841,12 +841,12 @@ The [[http://adl.github.io/hoaf/][HOA format]] inherits several features from th
 extends it in many ways, including support for non-deterministic
 automata, alternating automata, and for arbitrary acceptance conditions.
 
-#+BEGIN_SRC sh :exports results
+#+BEGIN_SRC sh :exports results :wrap SRC hoa
 ltldo ltl2dstar -f 'FGp0 | GFp1' --name=%f
 #+END_SRC
 
 #+RESULTS:
-#+begin_example
+#+begin_SRC hoa
 HOA: v1
 name: "FGp0 | GFp1"
 States: 4
@@ -878,7 +878,7 @@ State: 3 {1 3}
 [!0&1] 2
 [0&1] 3
 --END--
-#+end_example
+#+end_SRC
 
 #+NAME: hoa1
 #+BEGIN_SRC sh

doc/org/ltl2tgba.org

@@ -32,16 +32,16 @@ less frequent.)
 Formulas to translate may be specified using [[file:ioltl.org][common input options for
 LTL/PSL formulas]].
 
-#+BEGIN_SRC sh
+#+BEGIN_SRC sh :wrap SRC hoa
 ltl2tgba -f 'Fa & GFb'
 #+END_SRC
 
 #+RESULTS:
-#+begin_example
+#+begin_SRC hoa
 HOA: v1
 name: "Fa & GFb"
 States: 2
-Start: 1
+Start: 0
 AP: 2 "a" "b"
 acc-name: Buchi
 Acceptance: 1 Inf(0)
@@ -49,13 +49,13 @@ properties: trans-labels explicit-labels trans-acc complete
 properties: deterministic stutter-invariant
 --BODY--
 State: 0
-[1] 0 {0}
-[!1] 0
+[!0] 0
+[0] 1
 State: 1
-[0] 0
-[!0] 1
+[!1] 1
+[1] 1 {0}
 --END--
-#+end_example
+#+end_SRC
 
 Actually, because =ltl2tgba= is often used with a single formula
 passed on the command line, the =-f= option can be omitted and any

doc/org/ltldo.org

@@ -485,12 +485,12 @@ Instead of outputting the result of the translation of each formula by each
 translator, =ltldo= can also be configured to output the smallest
 automaton obtained for each formula:
 
-#+BEGIN_SRC sh
+#+BEGIN_SRC sh :wrap SRC hoa
 ltldo ltl2ba ltl3ba 'ltl2tgba -s' -f 'F(a & Xa | FGa)' --smallest
 #+END_SRC
 
 #+RESULTS:
-#+begin_example
+#+begin_SRC hoa
 HOA: v1
 States: 3
 Start: 0
@@ -507,7 +507,7 @@ State: 1
 State: 2 {0}
 [t] 2
 --END--
-#+end_example
+#+end_SRC
 
 Therefore, in practice, =ltldo --smallest trans1 trans2 trans3...=
 acts like a portfolio of translators, always returning the smallest