chore: move declarations to visitor function and other clean-up

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: na
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: passed
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: na
  - task: lint_javascript_tests
    status: na
  - task: lint_javascript_benchmarks
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  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
  - task: lint_c_examples
    status: na
  - task: lint_c_benchmarks
    status: na
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
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  - task: lint_typescript_declarations
    status: na
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: Planeshifter

lib/node_modules/@stdlib/_tools/remark/plugins/remark-lint-expected-html-sections/lib/linter.js

@@ -28,7 +28,8 @@ var keys = require( '@stdlib/utils/keys' );
 // VARIABLES //
 
 var debug = logger( 'remark-lint-expected-html-sections' );
-var SECTION_START = /<section(?:\s+class="([^"]*)")?>/;
+var RE_SECTION_START = /<section(?:\s+class="([^"]*)")?>/;
+var RE_SECTION_END = /<\/section>/;
 
 
 // MAIN //
@@ -56,12 +57,9 @@ function factory( options ) {
 		var requiredRootSections;
 		var requiredCSections;
 		var sectionStructure;
-		var currentSection;
 		var sectionsFound;
 		var sectionStack;
-		var sectionMatch;
 		var missingRoot;
-		var className;
 		var missingC;
 		var schema;
 		var msg;
@@ -135,10 +133,14 @@ function factory( options ) {
 		* @returns {void}
 		*/
 		function visitor( node ) {
+			var currentSection;
+			var sectionMatch;
+			var className;
+
 			// Check if this is a section start tag:
-			sectionMatch = SECTION_START.exec( node.value );
+			sectionMatch = RE_SECTION_START.exec( node.value );
 			if ( sectionMatch ) {
-				className = sectionMatch[1] || '';
+				className = sectionMatch[ 1 ] || '';
 
 				debug( 'Found section with class: %s', className );
 
@@ -169,7 +171,7 @@ function factory( options ) {
 				sectionStack.push( currentSection );
 			}
 			// Check if this is a section end tag:
-			else if ( /<\/section>/.test( node.value ) ) {
+			else if ( RE_SECTION_END.test( node.value ) ) {
 				if ( sectionStack.length > 0 ) {
 					sectionStack.pop();
 				}