Fix dead links

docs/pages/pmd/userdocs/cli_reference.md

@@ -198,5 +198,5 @@ Example:
 ## Available Report Formats
 
 PMD comes with many different renderers.
-All formats are described at [PMD Report formats](pmd_userdos_report_formats.html)
+All formats are described at [PMD Report formats](pmd_userdocs_report_formats.html)
 

pmd-doc/src/main/java/net/sourceforge/pmd/docs/DeadLinksChecker.java

@@ -177,6 +177,12 @@ public class DeadLinksChecker {
                         } else {
                             linkOk = linkTarget.isEmpty() || htmlPages.contains(linkTarget);
                         }
+
+                        // maybe a local file
+                        if (!linkOk) {
+                            Path localResource = docsDirectory.resolve(linkTarget);
+                            linkOk = Files.exists(localResource);
+                        }
                     }
 
                     if (!linkOk) {