chore: add dockerfiles directory for custom container definitions

Track custom Dockerfiles created for repositories
that don't include native container definitions.

Organized by service name in dockerfiles/ subdirectory:
- kicad-mcp
- blender-mcp
- freecad-mcp
- docker-mcp
- proxmox-mcp
- mcp-cloudron
- bash-language-server
- context7-mcp
- ghost-mcp
- discourse-mcp
- matomo-mcp
- gimp-mcp
- snipeit-mcp
- wordpress-mcp
- drawio-mcp
- audiobook-mcp

💘 Generated with Crush

Assisted-by: GLM-4.7 via Crush <crush@charm.land>

dockerfiles/context7-mcp/Dockerfile

@@ -0,0 +1,16 @@
+FROM node:22-alpine
+
+# Install pnpm for monorepo
+RUN npm install -g pnpm
+
+WORKDIR /app
+
+COPY package.json pnpm-lock.yaml ./
+
+RUN pnpm install --frozen-lockfile
+
+COPY . .
+
+RUN pnpm --filter @upstash/context7-mcp build
+
+CMD ["node", "packages/mcp/dist/index.js", "--transport", "stdio"]