improved instructions for creating an off-line diagrammer

ICSharpCode.ILSpyX/MermaidDiagrammer/html/template.html

@@ -170,7 +170,7 @@
             <div id="build-info" class="scndry horizontal collapse flx col">
                 <span>built from {{SourceAssemblyName}} v{{SourceAssemblyVersion}} and mermaid.js from CDN
                     <a target="_blank" href="https://cdn.jsdelivr.net/npm/mermaid@11.4.0/dist/mermaid.min.js" download="mermaid.min.js"
-                        title="For off-line use, download a copy and save it with the diagrammer - at the bottom of which you find a script with a reference to the mermaid CDN. Replace its 'src' with the path to your local copy.">📥</a>
+                        title="For off-line use, download a copy and save it in the diagrammer folder. At the bottom of the index.html you'll find a script with a reference to the mermaid CDN. Replace its 'src' with the file name of your local copy, e.g. 'mermaid.min.js'.">📥</a>
                 </span>
                 <span>
                     using <a class="project" target="_blank" href="{{RepoUrl}}#readme" title="🤿 get learned and find out about or 🔱 fork the project">ICSharpCode.ILSpyX</a> v{{BuilderVersion}}