fix badge and link to 3.9 documentation

.badges/maturity.svg

 <?xml version="1.0" encoding="UTF-8" ?>
-<svg xmlns="http://www.w3.org/2000/svg" width="91" height="20">
+<svg xmlns="http://www.w3.org/2000/svg" width="177" height="20">
   <linearGradient id="b" x2="0" y2="100%">
     <stop offset="0" stop-color="#bbb" stop-opacity=".1" />
     <stop offset="1" stop-opacity=".1" />
   </linearGradient>
   <mask id="anybadge_1">
@@ -3,8 +3,8 @@
   <linearGradient id="b" x2="0" y2="100%">
     <stop offset="0" stop-color="#bbb" stop-opacity=".1" />
     <stop offset="1" stop-opacity=".1" />
   </linearGradient>
   <mask id="anybadge_1">
-    <rect width="91" height="20" rx="3" fill="#fff" />
+    <rect width="177" height="20" rx="3" fill="#fff" />
   </mask>
   <g mask="url(#anybadge_1)">
@@ -9,8 +9,8 @@
   </mask>
   <g mask="url(#anybadge_1)">
-    <path fill="#555" d="M0 0h44v20H0z" />
-    <path fill="#4c1" d="M44 0h47v20H44z" />
-    <path fill="url(#b)" d="M0 0h91v20H0z" />
+    <path fill="#555" d="M0 0h61v20H0z" />
+    <path fill="#4c1" d="M61 0h116v20H61z" />
+    <path fill="url(#b)" d="M0 0h177v20H0z" />
   </g>
   <g
     fill="#fff"
@@ -18,8 +18,8 @@
     font-family="DejaVu Sans,Verdana,Geneva,sans-serif"
     font-size="11"
   >
-    <text x="23.0" y="15" fill="#010101" fill-opacity=".3">pylint</text>
-    <text x="22.0" y="14">pylint</text>
+    <text x="31.5" y="15" fill="#010101" fill-opacity=".3">maturity</text>
+    <text x="30.5" y="14">maturity</text>
   </g>
   <g
     fill="#fff"
@@ -27,7 +27,7 @@
     font-family="DejaVu Sans,Verdana,Geneva,sans-serif"
     font-size="11"
   >
-    <text x="68.5" y="15" fill="#010101" fill-opacity=".3">Stable</text>
-    <text x="67.5" y="14">Stable</text>
+    <text x="120.0" y="15" fill="#010101" fill-opacity=".3">Production/Stable</text>
+    <text x="119.0" y="14">Production/Stable</text>
   </g>
 </svg>

doc/conf.py

@@ -60,7 +60,7 @@
 
 # General information about the project.
 project = d["name"]
-copyright = "2018, XCG Consulting"
+copyright = "2018, 2022 XCG Consulting"
 author = d["author"]
 module_nospace = project.replace(" ", "")
 module_description = d.get("summary", "")
@@ -142,8 +142,7 @@
     )
 ]
 
-# Example configuration for intersphinx: refer to the Python standard library.
-intersphinx_mapping = {"https://docs.python.org/3/": None}
+intersphinx_mapping = {"https://docs.python.org/3.9/": None}
 
 
 #