lesson.scss: HTML block

carpentries/styles#519

Author: maxim-belkin

assets/css/lesson.scss

@@ -68,6 +68,7 @@ div.language-bash::before   { content: "Bash"; }
 div.language-c::before      { content: "C"; }
 div.language-cmake::before  { content: "CMake"; }
 div.language-cpp::before    { content: "C++"; }
+div.language-html::before   { content: "HTML"; }
 div.language-make::before   { content: "Make"; }
 div.language-matlab::before { content: "MATLAB"; }
 div.language-python::before { content: "Python"; }