adjust anchor tag generation to mirror github's assignment pattern

lib/index.js

@@ -86,7 +86,7 @@ class Page {
     } else {
       const prior = this.documentation.pages.slice(0, this.#index)
       const existing = prior.filter(({ rawKey }) => rawKey === this.rawKey)
-      const ending = existing.length ? `_${existing.length + 1}` : ''
+      const ending = existing.length ? `-${existing.length}` : ''
       this.key = `${this.rawKey}${ending}`
     }
 
@@ -125,11 +125,9 @@ class Page {
   // generates the raw un-deduped key value for page
   get rawKey () {
     return (
-      (this.title || this.#file)
-        .replace(/[^a-zA-Z0-9]+/g, ' ')
-        .trim()
-        .replace(/\s+/g, '-')
-        .toLowerCase() ||
+      this.#file
+        .replace(/[^a-zA-Z0-9]+/g, '')
+        .trim() ||
       'page'
     )
   }
@@ -154,15 +152,18 @@ class Section {
 
     // assigns unique key value for section
     const prior = [
-      ...this.documentation.pages,
+      this.page.title
+        .replace(/[^a-zA-Z0-9]+/g, ' ')
+        .trim()
+        .replace(/\s+/g, '-')
+        .toLowerCase(),
       ...this.page.sections
         .map(section => [section, ...section.subsections])
         .flat()
+        .map(({ rawKey }) => rawKey)
     ]
-    const existing = prior.filter(({ rawKey }) => rawKey === this.rawKey)
-    const ending = (existing.length || ['section', 'subsection'].includes(this.rawKey))
-      ? `_${existing.length + 1}`
-      : ''
+    const existing = prior.filter(rawKey => rawKey === this.rawKey)
+    const ending = existing.length ? `-${existing.length}` : ''
 
     this.key = `${this.rawKey}${ending}`
   }
@@ -209,12 +210,6 @@ class Section {
       .toLowerCase()
     if (baseKey) return baseKey
 
-    const sectionKey = this.section?.rawKey
-    if (sectionKey && sectionKey !== 'section') return sectionKey
-
-    const pageKey = this.page?.rawKey
-    if (pageKey && pageKey !== 'page') return pageKey
-
     return this.section ? 'subsection' : 'section'
   }