Make the 'open in editor' behaviour configurable

[jonsugar]

Once Lambo has finished bootstrapping a new project it automatically opens it in the configured editor—this behavior should be configurable.

By default, Lambo should NOT open the project for editing.

Configuring Open In Editor functionality
Add/set the OPEN_EDITOR property in ~/.lambo/config.

# Enable opening in editor
OPEN_EDITOR=true

# disable opening in the editor (default, can be omitted)
OPEN_EDITOR=false

Upgrading existing installations

# ------------------------------------------------------------------------------
# 14-Aug-2021 11:40 am (auto-generated by Lambo)
# ------------------------------------------------------------------------------
# Lambo has introduced new configuration options. They have been added here with
# sensible defaults; however, you should review them.
# ------------------------------------------------------------------------------

# Configure whether Lambo should open the new project in an editor.
#
# NOTE: Set to true to maintain current behavior.
#
# Possible values:
#   true, 1, "yes" or "on"
#   false (default), 0, "no" or "off"
# Set to true to maintain current behavior
OPEN_EDITOR=true