Add initial .editorconfig and extra markdownlint rules (#25293)

.editorconfig

@@ -0,0 +1,17 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = crlf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+
+[*.{cs,cshtml,html,razor}]
+indent_size = 4
+
+[*.cs]
+dotnet_sort_system_directives_first = true
+
+[*.md]
+max_line_length = off

.markdownlint.json

@@ -4,6 +4,9 @@
     "blanks-around-lists": false,
     "blanks-around-fences": false,
     "blanks-around-headers": true,
+    "emphasis-style": {
+      "style": "asterisk"
+    },
     "fenced-code-language": true,
     "first-header-h1": false,
     "first-line-h1": false,
@@ -61,5 +64,11 @@
     },
     "required-headers": false,
     "single-h1": false,
-    "ul-start-left": false
+    "strong-style": {
+      "style": "asterisk"
+    },
+    "ul-start-left": false,
+    "ul-style": {
+      "style": "asterisk"
+    }
 }