chore: readme again

README.md

@@ -6,9 +6,7 @@
 
 A tool to print webpages as PDF files, powered by [chromedp](https://github.com/chromedp/chromedp) and the [DevTools Protocol](https://chromedevtools.github.io/devtools-protocol/).
 
-## Usage
-
-### Go package
+## Go package
 
 Install with:
 ```shell
@@ -18,7 +16,7 @@ go get github.com/chialab/print2pdf-go/print2pdf
 and use it in your project. See the [package reference](https://pkg.go.dev/github.com/chialab/print2pdf-go/print2pdf)
 or the [plain](plain) application for an example.
 
-### REST application
+## REST application
 
 The `plain` directory in this repository contains a minimal REST application. It is also provided as a
 binary for each [release](https://github.com/chialab/print2pdf-go/releases/latest).
@@ -56,7 +54,7 @@ error, and a log line will be written to the console with more details.
 The endpoint also supports CORS headers. By default it allows requests from any origin, but this can customized
 by setting the `CORS_ALLOWED_HOSTS` environmental variable to a comma-separated list of allowed origins.
 
-### Lambda function
+## Lambda function
 
 The `lambda` directory in this repository contains a lambda function, to be run on AWS Lambda. It is also provided as a
 binary for each [release](https://github.com/chialab/print2pdf-go/releases/latest).
@@ -66,7 +64,7 @@ API Gateway so the request body [is a bit different](https://docs.aws.amazon.com
 
 To use it locally, see the docker image usage.
 
-### Docker image
+## Docker image
 
 Docker images for the `plain` and `lambda` applications are provided. They both come with Chromium pre-installed. Beware that
 there is no `latest` tag, only version specific ones. See [here](https://github.com/chialab/print2pdf-go/pkgs/container/print2pdf)