Markdown linter (#1309)

* Add markdown linting

- add linter default rules
- adapt rules to current code
- fix the code for linting to pass
- add CI check

fix #1243

* Fix markdown for Substrate
* Fix tooling install
* Fix workflow
* Add documentation
* Remove trailing spaces
* Update .github/.markdownlint.yaml

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
* Fix mangled markdown/lists
* Fix captalization issues on known words

cumulus/docs/container.md

@@ -1,19 +1,22 @@
-## Using Containers
+# Using Containers
 
-Using containers via **Podman** or **Docker** brings benefit, whether it is to build a container image or
-run a node while keeping a minimum footprint on your local system.
+Using containers via **Podman** or **Docker** brings benefit, whether it is to build a container image or run a node
+while keeping a minimum footprint on your local system.
 
-This document mentions using `podman` or `docker`. Those are usually interchangeable and it is encouraged using preferably **Podman**. If you have podman installed and want to use all the commands mentioned below, you can simply create an alias with `alias docker=podman`.
+This document mentions using `podman` or `docker`. Those are usually interchangeable and it is encouraged using
+preferably **Podman**. If you have podman installed and want to use all the commands mentioned below, you can simply
+create an alias with `alias docker=podman`.
 
 There are a few options to build a node within a container and inject a binary inside an image.
 
-### Parity built container image
+## Parity built container image
 
 Parity builds and publishes a container image that can be found as `docker.io/parity/polkadot-parachain`.
 
-### Parity CI image
+## Parity CI image
 
-Parity maintains and uses internally a generic "CI" image that can be used as a base to build binaries: [Parity CI container image](https://github.com/paritytech/scripts/tree/master/dockerfiles/ci-linux):
+Parity maintains and uses internally a generic "CI" image that can be used as a base to build binaries: [Parity CI
+container image](https://github.com/paritytech/scripts/tree/master/dockerfiles/ci-linux):
 
 The command below allows building a Linux binary without having to even install Rust or any dependency locally:
 
@@ -29,19 +32,22 @@ sudo chown -R $(id -u):$(id -g) target/
 If you want to reproduce other steps of CI process you can use the following
 [guide](https://github.com/paritytech/scripts#gitlab-ci-for-building-docker-images).
 
-### Injected image
+## Injected image
 
-Injecting a binary inside a base image is the quickest option to get a working container image. This only works if you were able to build a Linux binary, either locally, or using a container as described above.
+Injecting a binary inside a base image is the quickest option to get a working container image. This only works if you
+were able to build a Linux binary, either locally, or using a container as described above.
 
-After building a Linux binary ()`polkadot-parachain`) with cargo or with Parity CI image as documented above, the following command allows producing a new container image where the compiled binary is injected:
+After building a Linux binary ()`polkadot-parachain`) with cargo or with Parity CI image as documented above, the
+following command allows producing a new container image where the compiled binary is injected:
 
 ```bash
 ./docker/scripts/build-injected-image.sh
 ```
 
-### Container build
+## Container build
 
-Alternatively, you can build an image with a builder pattern. This options takes a while but offers a simple method for anyone to get a working container image without requiring any of the Rust toolchain installed locally.
+Alternatively, you can build an image with a builder pattern. This options takes a while but offers a simple method for
+anyone to get a working container image without requiring any of the Rust toolchain installed locally.
 
 ```bash
 docker build \