Update links

Author: jason-fox

.github/dita-ot/theme.css

@@ -6,4 +6,4 @@
   --bs-primary-border-subtle: #2f5b3a;
   --bs-primary-rgb: 78, 151, 96;
   --bs-primary-text-emphasis: #2e703f;
-}
+}

dita/extend.css/usage.dita

@@ -69,14 +69,9 @@
             </fig>
             <p>
                Working examples can be found in the <xref
-          href="http://swaggerdita-ot.rtfd.io/"
-          format="html"
-          scope="external"
-        >DITA-OT Swagger plug-in</xref> and <xref
-          href="https://prismjsdita-ot.rtfd.io/"
-          format="html"
-          scope="external"
-        >DITA-OT
+          href="../swagger/index.dita"
+          format="dita"
+        >DITA-OT Swagger plug-in</xref> and <xref href="../prismjs/index.dita" format="dita">DITA-OT
                Prism-JS plug-in</xref> repositories.
             </p>
         </section>

dita/readthedocs/index.dita

@@ -45,9 +45,8 @@
                    previous heading. To ensure this, it is recommended to prettify the existing
                    markdown using <xref href="https://prettier.io" format="html" scope="external">prettier</xref>
                    and fix the markup levels using the <xref
-            href="https://dita-validator-for-dita-ot.readthedocs.io/en/latest/"
-            format="html"
-            scope="external"
+            href="../validate.svrl/index.dita"
+            format="dita"
           >DITA Validator</xref><option>fix-dita</option>
                    transform.
                 </p>