Fixs/reviews setups (#3067)

* update syntax to POSIX

The function keyword is not recognize by every POSIX-compliant shell.  The function keyword is a bashism, a bash extension. POSIX syntax does not use function and mandates the use of parenthesis.

This commit fixes the two issues :
./linux/provision-postgres-linux.sh: 9: function: not found
./linux/provision-postgres-linux.sh: 15: Syntax error: "}" unexpected

* update path init.sql

* update steps numbers yarn setup

There were two number 3's, everything should be correct now.

* delete useless -e

packages/twenty-docs/docs/contributor/local-setup/yarn-setup.mdx

@@ -154,7 +154,7 @@ You can access this using `twenty` postgres user (password: `twenty`)
 </Tabs>
 
 
-## Step 3: Setup environment variables
+## Step 4: Setup environment variables
 
 Twenty requires you to set some environment variables. Locally, you should set them through a `.env` file.
 
@@ -164,7 +164,7 @@ cp ./packages/twenty-front/.env.example ./packages/twenty-front/.env
 cp ./packages/twenty-server/.env.example ./packages/twenty-server/.env
 ```
 
-## Step 4: Installing dependencies
+## Step 5: Installing dependencies
 
 :::info
 
@@ -180,7 +180,7 @@ nvm use #recommended
 yarn
 ```
 
-## Step 5: Running the project
+## Step 6: Running the project
 
 Setup your database with the following command:
 ```bash