MDL-36558 tool_elementlibrary: initial commit
MDL-36558 tool_elementlibrary: first attempt at pluggable elements
MDL-36558 tool_elementlibrary: move hardcoded examples into a library
MDL-36558 tool_elementlibrary: fix urls and remove remaining totara-specific elements
MDL-36558 tool_elementlibrary: add syntax highlighting and an example of how to dynamically generate examples
MDL-36558 tool_elementlibrary: add paging bar examples