Rename the [Ee]xts dir to ext (#38852)

**WARNING:** This PR will probably blow up all in-flight PRs

at some point in the early days of CmdPal, two of us created seperate
`Exts` and `exts` dirs. Depending on what the casing was on the branch
that you checked one of those out from, it'd get stuck like that on your
PC forever.

Windows didn't care, so we never noticed.

But GitHub does care, and now browsing the source on GitHub is basically
impossible.

Closes #38081

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowsSettings/WindowsSettings.schema.json

@@ -0,0 +1,73 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema",
+  "additionalProperties": false,
+  "required": [ "Settings" ],
+  "properties": {
+    "$schema": {
+      "description": "Path to the schema file.",
+      "type": "string"
+    },
+    "Settings": {
+      "description": "A list with all possible windows settings.",
+      "type": "array",
+      "items": {
+        "additionalProperties": false,
+        "required": [ "Name", "Command", "Type" ],
+        "type": "object",
+        "properties": {
+          "Name": {
+            "description": "The name of this setting.",
+            "type": "string"
+          },
+          "Areas": {
+            "description": "A list of areas of this setting",
+            "type": "array",
+            "items": {
+              "description": "A area of this setting",
+              "type": "string",
+              "pattern": "^Area"
+            }
+          },
+          "Type": {
+            "description": "The type of this setting.",
+            "type": "string",
+            "pattern": "^App"
+          },
+          "AltNames": {
+            "description": "A list with alternative names for this setting",
+            "type": "array",
+            "items": {
+              "description": "A alternative name for this setting",
+              "type": "string"
+            }
+          },
+          "Command": {
+            "description": "The command for this setting.",
+            "type": "string"
+          },
+          "Note": {
+            "description": "A additional note for this setting.",
+            "type": "string",
+            "pattern": "^Note"
+          },
+          "DeprecatedInBuild": {
+            "description": "The Windows build since this settings is not longer present.",
+            "type": "integer",
+            "minimum": 0,
+            "maximum": 4294967295
+          },
+          "IntroducedInBuild": {
+            "description": "The minimum need Windows build for this setting.",
+            "type": "integer",
+            "minimum": 0,
+            "maximum": 4294967295
+          },
+          "ShowAsFirstResult": {
+            "description": "Use a higher score as normal for this setting to show it as one of the first results.",
+            "type": "boolean"
+          }
+        }
+      }
+    }
+  }
+}