Automated snippet conversion by scripts

These changes are purely mechanical to differentiate them from manual
fixes/adjustments made in the next commit.
This results in broken code as some snippets contain errors.

Made in four steps:
1. Run ./migrate-snippet.py that converts `.md` files to code files
   and perhaps adds missing lines under `// @hide` comments.
2. Sort Java imports.
3. Remove old `.md` files.
4. Run ./generate.md to produce `*/generated/*.md` files.

qdrant-landing/content/documentation/headless/snippets/delete-collection/simple/bash.sh

@@ -0,0 +1 @@
+curl -X DELETE http://localhost:6333/collections/{collection_name}

qdrant-landing/content/documentation/headless/snippets/delete-collection/simple/csharp.cs

@@ -0,0 +1,9 @@
+
+
+public class Snippet
+{
+	public static async Task Run()
+	{
+		await client.DeleteCollectionAsync("{collection_name}");
+	}
+}

qdrant-landing/content/documentation/headless/snippets/delete-collection/simple/go.go

@@ -0,0 +1,7 @@
+package snippet
+
+import "context"
+
+func Main() {
+	client.DeleteCollection(context.Background(), "{collection_name}")
+}

qdrant-landing/content/documentation/headless/snippets/delete-collection/simple/java.java

@@ -0,0 +1,7 @@
+package com.example.snippets_amalgamation;
+
+public class Snippet {
+        public static void run() throws Exception {
+                client.deleteCollectionAsync("{collection_name}").get();
+        }
+}

qdrant-landing/content/documentation/headless/snippets/delete-collection/simple/python.py

@@ -0,0 +1,5 @@
+from qdrant_client import QdrantClient  # @hide
+
+client = QdrantClient(url="http://localhost:6333")  # @hide
+
+client.delete_collection(collection_name="{collection_name}")

qdrant-landing/content/documentation/headless/snippets/delete-collection/simple/rust.rs

@@ -0,0 +1,7 @@
+
+
+pub async fn main() -> anyhow::Result<()> {
+    client.delete_collection("{collection_name}").await?;
+
+    Ok(())
+}

qdrant-landing/content/documentation/headless/snippets/delete-collection/simple/typescript.ts

@@ -0,0 +1,5 @@
+import { QdrantClient } from "@qdrant/js-client-rest"; // @hide
+
+const client = new QdrantClient({ host: "localhost", port: 6333 }); // @hide
+
+client.deleteCollection("{collection_name}");