install.sh https option

Author: steam0r

md/6_1_developing_cables/1_setup_dev_env/setup_dev_env.md

@@ -30,7 +30,7 @@ But let's get started:
 ## Common
 - install [Node Version Manager](https://github.com/nvm-sh/nvm#install--update-script)
 - close and reopen your terminal, make sure nvm is installed properly, `nvm --version` should output some version number
-- run `./install_local.sh`
+- run `./install_local.sh` (if you prefer https over public-key auth, run `./install_local.sh https`)
     - this will:
         - install the required node version (and set it as default in `nvm`)
         - check out all needed repositories into subdirectories

md/6_1_developing_cables/2_helper_scripts/helper_scripts.md

@@ -9,6 +9,8 @@ enters all repositories and runs `npm run build`
 tries to guess your OS, installs dependencies, creates needed directories and files and copies
 `cables_example.json` to `cables.json` if it does not exist
 
+if you do not authenticate to github via public key, add `https` as a parameter
+
 ## update_repos.sh
 
 reads the current nodeversion vom .nvmrc and walks the repositories,