increase material-mkdocs version and add plugin installation

mkdocs:

  image:

    name: squidfunk/mkdocs-material:6.1.5

    name: squidfunk/mkdocs-material:6.1.7

    entrypoint: [""]

  stage: build

  variables:

    MKDOCS_OUTPUT_PATH: 'documentation_build/'

  script:

    - pip3 install mkdocs-awesome-pages-plugin==2.4.0

    - pip3 install mkdocs-git-revision-date-localized-plugin==0.7.2

    - pip3 install mkdocs-macros-plugin==0.5.0

    - mkdocs build -d "$MKDOCS_OUTPUT_PATH"

* Update material for mkdocs version to 6.1.7

* Add mkdocs-awesome-pages plugin