Fix C++ Code Block Highlighting in Markdown Rendering (#463)

* Add temporary page at /issue305 to test the styling

* Add example C++, Swift, and JavaScript code block to /issue305

* Add syntax highlighting for C++ language

* Add syntax highlighting for C++ code having .language-c++ class

* Improve syntax highlighting for C++ code

* Remove temporary page (/issue305)

* Add comment against C++ exclusive classes for better readability

Author: ishaanbedi

assets/stylesheets/_syntax.scss

@@ -118,3 +118,17 @@
 .language-console {
   color: var(--color-syntax-plain-text);
 }
+
+
+// Explicit syntax highlighting for C++ code blocks:
+
+.language-cpp .cp,
+.language-cpp .kt,
+.language-cpp .nl,
+.language-cpp .o,
+.language-c\+\+ .cp,
+.language-c\+\+ .kt,
+.language-c\+\+ .nl,
+.language-c\+\+ .o {
+  color: var(--color-syntax-keywords);
+}