Disambiguate free pascal and puppet

[tancnle]

Both free pascal and puppet are sharing the same file extension, that is .pp. This change adds .pp as a possible extension for the pascal lexer and disambiguates between puppet and pascal using keywords.

Addresses #1842

[tancnle]

@Alexey-T could you help to review this PR and verify if it addresses the reported issue? 🙏🏼

[Alexey-T]

            function Name : integer;
            begin
              Name := 2;
              Name := Name + 1
            end.

not correct snippet! end with dot is only at the end of UNIT FILE, but end of a function has end;.

[tancnle]

not correct snippet! end with dot is only at the end of UNIT FILE, but end of a function has end;.

Gotcha 👍🏼. Thanks for noting this. I have fixed the snippet in the test and extended the rules to cater for both end; and end.