chore: add markdownlint config to disable overly strict rules

- Disable MD013 (line length) - not useful for documentation
- Disable MD033 (inline HTML) - sometimes needed
- Disable MD036 (emphasis as heading) - false positives
- Disable MD040 (fenced code language) - not always applicable
- Disable MD060 (table column style) - too pedantic about spacing

Author: trsdn

.markdownlint.json

@@ -0,0 +1,11 @@
+{
+  "default": true,
+  "MD013": false,
+  "MD033": false,
+  "MD036": false,
+  "MD040": false,
+  "MD060": false,
+  "MD032": {
+    "blank_lines_around": "lists"
+  }
+}