Verschiebe Themes in themes

Development.md

src/plainui/package.json

...b-high-contrast/hub-high-contrast-variables-bootstrap.css

...gh-contrast/hub-high-contrast-variables-bootstrap.css.map

...plainui/hub-high-contrast/hub-high-contrast-variables.css

...nui/hub-high-contrast/hub-high-contrast-variables.css.map

src/plainui/styles/hub-high-contrast.scss

src/plainui/styles/hub.scss

src/plainui/styles/themes/hub-high-contrast.scss

...-high-contrast/hub-high-contrast-variables-bootstrap.scss

...themes/hub-high-contrast/hub-high-contrast-variables.scss

src/plainui/styles/themes/hub.scss