[SYCL][Doc] Fix relative links handling for Sphinx (#2294)

Signed-off-by: Alexander Batashev <[email protected]>

Author: Alexander Batashev

sycl/doc/conf.py

@@ -53,6 +53,7 @@
 
 def on_missing_reference(app, env, node, contnode):
     if node['reftype'] == 'any':
+        contnode['refuri'] = "https://github.com/intel/llvm/tree/sycl/sycl/doc/" + contnode['refuri']
         return contnode
     else:
         return None