added custom renderer

lang.json

theme/old-templates/article.html

theme/old-templates/base.html

theme/old-templates/category.html

theme/old-templates/index.html

theme/old-templates/macros/README.md

theme/old-templates/macros/cards.html

theme/old-templates/macros/getters.html

theme/old-templates/macros/renderers.html

theme/old-templates/page.html

theme/old-templates/tag.html

theme/templates/base.html

theme/templates/macros/README.md

theme/templates/macros/content_renderer.html

theme/templates/macros/renderers.html

theme/templates/page.html