docs: uniform codeblocs => use shell language + add title

Signed-off-by: Guillaume de Rouville <guillaume.derouville@gmail.com>

docs/learn/101-use.md

@@ -22,7 +22,7 @@ First, you'll need to make sure [you have installed dagger on your local machine
 
 **Step 1**: Clone the example repository
 
-```sh
+```shell
 git clone https://github.com/dagger/examples.git
 ```
 
@@ -32,7 +32,7 @@ git clone https://github.com/dagger/examples.git
 
 Go to the app directory:
 
-```sh
+```shell
 cd ./examples/todoapp
 ```
 
@@ -46,7 +46,7 @@ dagger input list || curl -sfL https://releases.dagger.io/examples/key.txt >> ~/
 
 **Step 4**: Deploy!
 
-```sh
+```shell
 dagger up
 ```
 
@@ -56,7 +56,7 @@ At the end of the deploy, you should see a list of outputs. There is one that is
 
 This repository is already configured to deploy the code in the directory `./todoapp`, so you can change some code (or replace the app code with another react app!) and re-run the following command to re-deploy when you want your changes to be live:
 
-```sh
+```shell
 dagger up
 ```
 
@@ -70,7 +70,7 @@ An Environment holds the entire deployment configuration.
 
 You can list existing environment from the `./todoapp` directory:
 
-```sh
+```shell
 dagger list
 ```
 
@@ -82,7 +82,7 @@ Each environment can have different kind of deployment code. For example, a `dev
 
 The plan is the deployment code, that includes the logic to deploy the local application to an AWS S3 bucket. From the `todoapp` directory, you can list the code of the plan:
 
-```sh
+```shell
 ls -l .dagger/env/s3/plan/
 ```
 
@@ -92,7 +92,7 @@ Any code change to the plan will be applied during the next `dagger up`.
 
 The plan can define one or several `inputs` in order to take some information from the user. Here is how to list the current inputs:
 
-```sh
+```shell
 dagger input list
 ```
 
@@ -102,7 +102,7 @@ The inputs are persisted inside the `.dagger` directory and pushed to your git r
 
 The plan defines one or several `outputs`. They can show useful information at the end of the deployment. That's how we read the deploy `url` at the end of the deployment. Here is the command to list all inputs:
 
-```sh
+```shell
 dagger output list
 ```