Wrong loading of plugins/locale breaks the app.

[asvny]

Describe the bug
Loading plugins before and then loading the locale for en breaks the app.

Expected behavior
Should work correctly without any error.

Information

• Day.js Version - 1.9.6
• OS: Mac
• Browser Chrome

Let's say we have code like this

dayjs.extend(advancedFormat);
dayjs.locale(require('dayjs/locale/en'))

// Then when you try to do 
dayjs().format('dddd, MMM Do, YYYY');

It breaks with an error d.ordinal is not a function. It is because there is no ordinal property in en.js file. More specifically this function https://github.com/iamkun/dayjs/blob/dev/src/plugin/advancedFormat/index.js#L6 should be moved to en.js file.

Repro - https://codesandbox.io/s/elegant-christian-hbsr7?file=/src/index.js

Happy to submit a PR.

[asvny]

Created a fix for it #1483

[ScoreUnder]

What is the correct order to load these in? I want to use the AdvancedFormat plugin to display day ordinals but I can't figure out how to avoid the r.ordinal is not a function bug.

[rizowski]

We are only using the AdvancedFormat plugin and getting the r.ordinal is not a function error. Doesn't state in the documentation that it requires any other plugins for using Do