doc,tools: properly syntax highlight API ref docs

Prior to this commit, all <pre> tags were being highlighted as JavaScript. This has been corrected to syntax highlight all languages appearing in the API reference docs. This was accomplished by using highlight.js instead of SHJS for the frontend lib. * remove SHJS JavaScript code * add highlight.js bundle * fix script tags to reflect replacement * migrate CSS to use highlight.js classes * add appropriate documentation * ensure api_assets README.md stays interal Fixes: #33363
nodejs · DerekNonGeneric · May 16, 2020 · May 17, 2020 · May 18, 2020 · May 18, 2020
commit 0bc8b9af44a06bf4b92b065bcc1af4934bde6735
diff --git a/Makefile b/Makefile
@@ -737,7 +737,7 @@ out/doc/api/assets:
 
 # If it's not a source tarball, we need to copy assets from doc/api_assets
 out/doc/api/assets/%: doc/api_assets/% out/doc/api/assets
-	@cp $< $@
+	@cp $< $@ ; $(RM) out/doc/api/assets/README.md
 
 
 run-npm-ci = $(PWD)/$(NPM) ci

diff --git a/doc/api_assets/README.md b/doc/api_assets/README.md
@@ -0,0 +1,27 @@
+# API Reference Document Assets
+
+## highlight.pack.js
+
+_Generated by [highlightjs.org/download][] on 2020-05-16._
+
+Grammars included in the custom bundle:
+
+* Bash
+* C
+* C++
+* CoffeeScript
+* JavaScript
+* JSON
+* Markdown
+* Plaintext
+* Shell Session
+
+## sh.css
+
+The syntax theme for code snippets in API reference documents.
+
+## style.css
+
+The main stylesheet for API reference documents.
+
+[highlightjs.org/download]: https://highlightjs.org/download/
diff --git a/doc/api_assets/highlight.pack.js b/doc/api_assets/highlight.pack.js
diff --git a/doc/api_assets/sh.css b/doc/api_assets/sh.css
@@ -1,25 +1,23 @@
-.sh_sourceCode {
+.hljs {
   font-weight: normal;
   font-style: normal;
 }
 
-.sh_sourceCode .sh_symbol,
-.sh_sourceCode .sh_cbracket {
+.hljs-symbol {
   color: #333;
 }
 
-.sh_sourceCode .sh_keyword {
+.hljs-keyword {
   color: #338;
 }
 
-.sh_sourceCode .sh_string,
-.sh_sourceCode .sh_regexp,
-.sh_sourceCode .sh_number,
-.sh_sourceCode .sh_specialchar {
+.hljs-string,
+.hljs-regexp,
+.hljs-number {
   color: #E54305;
 }
 
-.sh_sourceCode .sh_comment {
+.hljs-comment {
   color: #666;
   font-weight: lighter;
 }
diff --git a/doc/api_assets/sh_javascript.min.js b/doc/api_assets/sh_javascript.min.js