chore: separate hanwritten and generated files in web-playground (vectordotdev#17871)

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closes: vectordotdev#17827 

I went with the simplest solution since we might do a major overhaul
later. It should be good enough for now.

Author: pront

lib/vector-vrl/web-playground/README.md

@@ -19,7 +19,7 @@ cargo install --locked --version 0.10.3 wasm-pack
 After installing `wasm-pack` we must compile our project by running:
 
 ```shell
-wasm-pack build --target web --out-dir public
+wasm-pack build --target web --out-dir public/pkg
 ```
 
 Notice the `public` directory was populated with `.wasm`, and `.js`,
@@ -41,6 +41,7 @@ the web browser console.
 To see this in action we host `index.html` locally, for example by running:
 
 ```shell
+cd public
 python3 -m http.server
 ```
 

lib/vector-vrl/web-playground/netlify.toml

@@ -11,7 +11,7 @@
   publish = "public/"
 
   # Default build command.
-  command = "bash ../../../scripts/ensure-wasm-pack-installed.sh && wasm-pack build --target web --out-dir public"
+  command = "bash ../../../scripts/ensure-wasm-pack-installed.sh && wasm-pack build --target web --out-dir public/pkg"
 
   # Ignore everything except the base directory and changes to vector/lib/
   ignore = "git diff --quiet $CACHED_COMMIT_REF $COMMIT_REF . ../../../lib"

lib/vector-vrl/web-playground/public/.gitignore

@@ -1,4 +1,4 @@
-import init, { run_vrl } from "./vector_vrl_web_playground.js";
+import init, { run_vrl } from "./pkg/vector_vrl_web_playground.js";
 import { vrlLanguageDefinition, vrlThemeDefinition } from "./vrl-highlighter.js";
 
 const PROGRAM_EDITOR_DEFAULT_VALUE = `# Remove some fields