Support linkcheck ignore per module documentation

If a linkcheck_ignore.json exists in the doc folder, it is loaded to extend
the linkcheck_ignore configuration of Sphinx.

modules/stock_shipment_cost_weight/doc/conf.py

@@ -85,4 +85,14 @@ intersphinx_mapping.update({
         })
 linkcheck_ignore = [r'/.*', r'https://demo.tryton.org/*']
 
+try:
+    with open(os.path.join(
+                os.path.dirname(__file__),
+                'linkcheck_ignore.json'), 'r') as f:
+        import json
+        linkcheck_ignore.extend(json.load(f))
+        del json
+except FileNotFoundError:
+    pass
+
 del get_info, info, base_url, modules_url, trytond_url