Revert "docs: valid section anchors"

This reverts commit 6053bf8.

Author: sdkrystian

share/mrdocs/addons/generator/asciidoc/layouts/overload-set.adoc.hbs

@@ -1,4 +1,6 @@
-[#{{replace (replace symbol.ref '/' '_') '.adoc' ''}}]
+{{#if relfileprefix}}:relfileprefix: {{relfileprefix}}{{/if}}
+[#{{#if (is_multipage)}}{{symbol.id}}{{else}}{{symbol.ref}}{{/if}}]
+
 = {{#if symbol.name}}Overload set {{>nested-name-specifier symbol=symbol.parent}}{{symbol.name}}{{else}}Unnamed overload set{{/if}}
 
 == Members

share/mrdocs/addons/generator/asciidoc/layouts/single-symbol.adoc.hbs

@@ -1,2 +1,4 @@
-[#{{replace (replace symbol.ref '/' '_') '.adoc' ''}}]
+{{#if relfileprefix}}:relfileprefix: {{relfileprefix}}{{/if}}
+[#{{#if (is_multipage)}}{{symbol.id}}{{else}}{{symbol.ref}}{{/if}}]
+
 {{> (concat 'symbols' '/' (lookup symbol 'kind')) symbol=symbol}}