Fixed Portuguese and Polish plurals and German translations (pacollin…

…s#75)

* WIP: plurals and German translations

https://github.com/marcelkraus/twietesla/blob/978fe99689adc1c38ce064f474ca554dfbcdfc1f/i18n/de.toml

* Added Austrian German support

* Generalized to German

* Fixed broken Polish plural form

Thanks to @skix123's comment in
gohugoio/hugo#3846 (comment),
I've found this solution.

References:

1. http://www.unicode.org/cldr/charts/28/supplemental/language_plural_rules.html
2. http://www.skwierzyna.net/polishgrammar.pdf
3. https://en.wikibooks.org/wiki/Polish/Nouns_-_Number
4. https://en.wikipedia.org/wiki/Polish_morphology#Nouns
5. https://qr.ae/TWrm97
6. Podręczny słownik francusko-polski, polsko-francuski, wydanie XVII

* Improved the French version of site description

* Also fixed Brazillian Portuguese plural

* Showed sample "German" post

Only the heading is "translated by Google".

* Changed languageCode: "br" → "pt"

exampleSite/config.toml

@@ -144,11 +144,48 @@ disableLanguages        = [""]
     LanguageName        = "English"
     weight              = 1
 
+  [Languages.de]
+    languageCode        = "de"
+    LanguageName        = "Deutsch"
+    title               = "Hugo Future Imperfect Slim auf deutsch"
+    description         = "Ein Thema von HTML5 UP, portiert von Julio Pescador.  Vereinfacht und verbessert von Patrick Collins. Mehrsprachig von StatnMap. Unterstützt von: Hugo. "
+    weight              = 2
+
+    [[Languages.de.menu.main]]
+      name              = "Startseite"
+      url               = "/"
+      identifier        = "fas fa-home"
+      weight            = 1
+
+    [[Languages.de.menu.main]]
+      name              = "Über mich"
+      url               = "/about/"
+      identifier        = "far fa-id-card"
+      weight            = 2
+
+    [[Languages.de.menu.main]]
+      name              = "Blog"
+      url               = "/blog/"
+      identifier        = "far fa-newspaper"
+      weight            = 3
+
+    [[Languages.de.menu.main]]
+      name              = "Kategorien"
+      url               = "/categories/"
+      identifier        = "fas fa-sitemap"
+      weight            = 5
+
+    [[Languages.de.menu.main]]
+      name              = "Kontakt"
+      url               = "/contact/"
+      identifier        = "far fa-envelope"
+      weight            = 6
+
   [Languages.fr]
     languageCode        = "fr"
     LanguageName        = "Français"
-    title               = "Hugo Future Imperfect Slim in fr"
-    description         = "Un thème de HTML5 UP, porté par Julio Pescador. Slimmed et amélioré par Patrick Collins. Multilingue par StatnMap. Propulsé par Hugo. "
+    title               = "Hugo Future Imperfect Slim en français"
+    description         = "Un thème par HTML5 UP, porté par Julio Pescador. Simplifié et amélioré par Patrick Collins. Multilingue par StatnMap. Propulsé par Hugo."
     weight              = 2
 
     [[Languages.fr.menu.main]]
@@ -218,38 +255,38 @@ disableLanguages        = [""]
       identifier        = "far fa-envelope"
       weight            = 6
 
-  [Languages.br]
-    languageCode        = "br"
+  [Languages.pt]
+    languageCode        = "pt"
     LanguageName        = "Português"
     title               = "Hugo Future Imperfect Slim em português"
     description         = "Um tema do HTML5 UP, portado por Julio Pescadora e reduzido por Patrick Collins. Multilíngue por StatnMap. Feito com Hugo."
     weight              = 4
 
-    [[Languages.br.menu.main]]
+    [[Languages.pt.menu.main]]
       name              = "Início"
       url               = "/"
       identifier        = "fas fa-home"
       weight            = 1
 
-    [[Languages.br.menu.main]]
+    [[Languages.pt.menu.main]]
       name              = "Sobre"
       url               = "/about/"
       identifier        = "far fa-id-card"
       weight            = 2
 
-    [[Languages.br.menu.main]]
+    [[Languages.pt.menu.main]]
       name              = "Blog"
       url               = "/blog/"
       identifier        = "far fa-newspaper"
       weight            = 3
 
-    [[Languages.br.menu.main]]
+    [[Languages.pt.menu.main]]
       name              = "Categorias"
       url               = "/categories/"
       identifier        = "fas fa-sitemap"
       weight            = 5
 
-    [[Languages.br.menu.main]]
+    [[Languages.pt.menu.main]]
       name              = "Contato"
       url               = "/contact/"
       identifier        = "far fa-envelope"