Add configuration to help users adjust duration to trigger alerts before an event occurs

This feature can work with Magic Mirror version after v2.11.0

In V5.0, we have:

1. Google Calendar:
   ...
2. Viet Nam Calendar:
   ...
3. General:

• Add config durationWillAlert to help user adjust the time to show alert before events occur

Fix alert sound and maybe done this module :)

This feature can work with Magic Mirror version after v2.11.0

In V4.0, we have:

1. Google Calendar:

• Remove check valid of google calendars, no error when user forgot input color or title
• Get default color if the user doesn't input in google calendars{}
• Get default title from email account if the user doesn't input in google calendars{}
• Add 2 configurations for handling Alert (alertSoundFile, alertSoundTimer)
• Add new soundtracks for alert
• Fix multiple alert sounds played when more events are coming
• Rename showLocation -> displayLocation
• Duration of alert sound and notification will base on alertSoundTimer

2. Viet Nam Calendar:

• ...

3. General:

• Add some translation text
• Fix RegExp to get id account from google calendars url

Re-construct events data and optimize to get them

This feature can work with Magic Mirror version after v2.11.0

In V3.0, we have:

1. Google Calendar:

• Calendar won't be error if we force delete calendar[]

2. Viet Nam Calendar

• Move source code to display VietNam events to other functions

3. General:

• Fix switch calendars
• Add page indicator of calendars
• Add 1 configuration (displayPageIndicator). Read more in README
• Add new classname (separateLine and indicactorPage)
• Rename of "currentCalIndex" -> "currentPage"
• Delete getInterval due to the system didn't re-invoke start() anymore
• Optimize layout and code

New switch features and more tidy code

This feature can work with Magic Mirror version after v2.11.0

In V2.0, we have:

1. Google Calendar:

• ...

2. Viet Nam Calendar

• Change the layout of the lunar date in VietNam events from top to bottom

3. General

• Update more detail about this module in README
• Optimize solution to switch calendars
• Add two buttons to forward calendar to next ( --> ) or previous ( <-- )
• Change configuration "displayButton" -> "displaySwitchButton"
• Tidy layout and code for reading easily. Will tidy more in next release
• Add 2 configurations (displayCalendarAfterInterval, calendarAfterInterval). Read more in README

Basic feature and old messy code

This feature can work with Magic Mirror version after v2.11.0

In V1.0, we have:

1. Google Calendar:

• Add more than one google calendar
• Can change color, and title name for each google calendar
• Button to switch between calendars
• Send alert notification if event will happen within 5'
• Play alert sound if event will happen within 5'
• Refresh all calendar every minute

2. Viet Nam Calendar

• Show lunar events in a month
• Show VietNam and international events in a month
• Show/hide lunar date of events
• Can add your personal events, and they only show in current month
• Can change color for VietName Calendar