Change on README, --path is being deprecated on bundle

Author: Alvaro Figueroa

README.md

@@ -15,7 +15,7 @@ you only have one image, place it in the 'original' folder.
 1. You need "ruby" and "ruby-bundler" installed locally.  These instructions
 were tested with ruby 2.5 and ruby-bundler 1.17.3 on a Debian Stretch system.
 2. As needed, `git submodule update --init --recursive` to fetch the submodules
-3. One time, run `bundle install --path vendor/bundle`
+3. One time, run `bundle config set path 'vendor/bundle' && bundle install ``
 4. Run `bundle exec jekyll serve` to generate the site locally
 5. Visit the displayed "server address"
 6. After most local edits, the content will be updated.  You will need to