Merge pull request #78 from tweag/yannham-patch-1

Update README.md

README.md

@@ -14,26 +14,31 @@ is a tool to generate Nickel contracts that describe the configuration schema
 expected by a set of Terraform providers.
 
 ## Starting a Tf-Ncl configuration
+
 The easiest way to get started is to use the `hello-tf` flake template:
-```shell
+
+```console
 nix flake init -t github:tweag/tf-ncl#hello-tf
 ```
+
 This will leave you with a `flake.nix` file containing some glue code for
 getting a Nickel contract out of `tf-ncl`, evaluating a Nickel configuration
 and calling Terraform. It's as easy as
-```shell
+
+```console
 nix develop -c run-terraform init
 nix develop -c run-terraform apply
 ```
 
 Without Nix it's a bit more complicated. You will need to obtain the Nickel
 contract using the tools in this repository. Take a look at [the working
-principle](how) for an overview of the process. The most involved step will be
+principle](#how) for an overview of the process. The most involved step will be
 calling `schema-merge` with extracted Terraform provider schemas, see [the nix
 code](nix/terraform_schema.nix) for inspiration.
 
 Once you have a project set up, you can start writing Nickel configuration
 code. To quote from the `hello-tf` example:
+
 ```nickel
 let Tf = import "./schema.ncl" in
 {
@@ -54,17 +59,20 @@ evaluates to a record satisfying the `Tf.Config` contract.
 To actually turn the Nickel code into a JSON configuration file understood by
 Terraform, you need to call `nickel` to export the `renderable_config` toplevel
 attribute introduced by the `Tf.Config` contract:
-```shell
-nickel export <<<'(import "./<your-toplevel-file>.ncl").renderable_config'
+
+```console
+nickel export <your-toplevel-file.ncl> --field renderable_config
 ```
+
 This can be useful for inspecting the result of your code. But usually it will
 be easier to use the wrapper script for Terraform provided in the [`hello-tf`
 flake template](examples/hello-tf/flake.nix).
 
 For inspiration on what's possible with Nickel, take a look at [the
 examples](examples/). Happy hacking!
 
-## How?
+## How
+
 Unfortunately, Terraform doesn't expose an interface for extracting a machine
 readable specification for the provider independent configuration it supports.
 Because of that this repository contains two tools and some glue written in
@@ -100,14 +108,17 @@ flowchart LR
 The entire process is packaged up in a Nix function `generateSchema` which is
 exposed as a flake output. Also, to generate a Nickel contract for a single
 provider, there is a flake output `schemas`:
-```shell
+
+```console
 nix build github:tweag/tf-ncl#schemas.aws
 ```
+
 All providers available in `nixpkgs` are supported. The `generateSchema`
 function can also be called manually. For example, to get a monolithic Nickel
 schema for the `aws`, `github` and `external` Terraform providers, you could
 use
-```shell
+
+```console
 nix build --impure --expr \
   '(builtins.getFlake "github:tweag/tf-ncl).generateSchema.${builtins.currentSystem} (p: { inherit (p) aws github external; })'
 ```