Update Markdown validations

.rules/custom.markdownlint.jsonc

@@ -0,0 +1,3 @@
+{
+    "line-length": 200
+}

.rules/yamllint.yml

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+# https://yamllint.readthedocs.io/en/stable/configuration.html#default-configuration
+
+extends: default
+
+rules:
+  anchors:
+    forbid-undeclared-aliases: true
+    forbid-duplicated-anchors: true
+
+  # 255 chars should be enough, but don't fail if a line is longer
+  line-length:
+    max: 200
+    #level: warning