DOC: Fix version switcher links to documentation

Author: melissawm

doc/_static/switcher.json

@@ -1,22 +1,27 @@
 [
     {
         "name": "3.5 (stable)",
-        "version": "stable"
+        "version": "stable",
+        "url": "https://matplotlib.org/stable"
     },
     {
         "name": "3.6 (dev)",
-        "version": "devdocs"
+        "version": "devdocs",
+        "url": "https://matplotlib.org/devdocs"
     },
     {
         "name": "3.4",
-        "version": "3.4.3"
+        "version": "3.4.3",
+        "url": "https://matplotlib.org/3.4.3"
     },
     {
         "name": "3.3",
-        "version": "3.3.4"
+        "version": "3.3.4",
+        "url": "https://matplotlib.org/3.3.4"
     },
     {
         "name": "2.2",
-        "version": "2.2.4"
+        "version": "2.2.4",
+        "url": "https://matplotlib.org/2.2.4"
     }
 ]

doc/conf.py

@@ -336,7 +336,6 @@ def matplotlib_reduced_latex_scraper(block, block_vars, gallery_conf,
     "show_prev_next": False,
     "switcher": {
         "json_url": "https://matplotlib.org/devdocs/_static/switcher.json",
-        "url_template": "https://matplotlib.org/{version}/",
         "version_match": (
             # The start version to show. This must be in switcher.json.
             # We either go to 'stable' or to 'devdocs'