all: do not commit generated JS/CSS to source control (#148)

Closes #125
Closes #40

Among other things, this moves all of the asset generation to run within
the context of an npm script. Developer documentation stubs have been
added so that people can get started more easily.

The top-level Dockerfile (which is no longer used in production) has
been removed as its presence has been causing confusion. This changeset
will break it anyways.

These changes will make for less "repo churn" as the static assets are
built and rebuilt, at the cost of making the build step more complicated
for downstream packagers. If this becomes a burden, we can explore
making a "release tarball" that contains pre-massaged outputs.

package.json

@@ -0,0 +1,23 @@
+{
+  "name": "@techaro/anubis",
+  "version": "1.0.0-see-VERSION-file",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "npm run assets && go test ./...",
+    "test:integration": "npm run assets && go test ./internal/test",
+    "assets": "./web/build.sh && ./xess/build.sh",
+    "dev": "npm run assets && go run ./cmd/anubis",
+    "container": "npm run assets && go run ./cmd/containerbuild"
+  },
+  "author": "",
+  "license": "ISC",
+  "devDependencies": {
+    "cssnano": "^7.0.6",
+    "cssnano-preset-advanced": "^7.0.6",
+    "postcss-cli": "^11.0.0",
+    "postcss-import": "^16.1.0",
+    "postcss-import-url": "^7.2.0",
+    "postcss-url": "^10.1.3"
+  }
+}