docs: valid section anchors

Author: alandefreitas

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

@@ -1,6 +1,4 @@
-{{#if relfileprefix}}:relfileprefix: {{relfileprefix}}{{/if}}
-[#{{#if (is_multipage)}}{{symbol.id}}{{else}}{{symbol.ref}}{{/if}}]
-
+[#{{replace (replace symbol.ref '/' '_') '.adoc' ''}}]
 = {{#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

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