pt-PT: rename to 'pt' and make this the primary variant for 'pt', not 'pt-BT'

docs/languages.md

 | `und`       | `und-fonipa`      |                       | Phonemes<sup>[3]</sup>      | IPA                    |
 | `zls`       | `pl`              | South Slavic          | Polish                      |                        |
 | `roa`       | `pt-BR`           | Romance               | Portuguese                  | Brazillian             |
-| `roa`       | `pt-PT`           | Romance               | Portuguese                  | Portugal               |
+| `roa`       | `pt`              | Romance               | Portuguese                  | Portugal               |
 | `inc`       | `pa`              | Indic                 | Punjabi                     |                        |
 | `roa`       | `ro`              | Romance               | Romanian                    |                        |
 | `zls`       | `ru`              | South Slavic          | Russian                     |                        |

espeak-ng-data/lang/roa/pt-PT → espeak-ng-data/lang/roa/pt

 name Portuguese (Portugal)
+language pt
 language pt-pt
-language pt 6
 phonemes pt-pt
 
 dictrules 1

espeak-ng-data/lang/roa/pt-BR

 name Portuguese (Brazil)
 language pt-br
-language pt
+language pt 6
 
 dictrules 2
 stressLength 200 115 230 230 0 0 250 270