Fix #891 - Adding site-wide and locale-specific support for changing the logo link

[dylburger]

Summary

This PR adds support for the feature requested in #891 : adding the option to change the link to which the user is directed when clicking the logo.

I ran across this issue on my own VuePress site: I'm keeping the default base URL (/), but have no content at /, only at /terms, /privacy, etc. We actually host a completely different app at the root of our domain, and handle routing to that app using Cloudfront cache behaviors. Specifically,

• https://domain.com -> directs user to different, core app (not VuePress)
• https://domain.com/terms -> directs user to VuePress site
• https://domain.com/privacy -> directs user to VuePress site

Since the router-link tied to the logo currently does client-side routing to /, and since I have no content at /, users get a 404. Since I'm handling routing at the Cloudfront-level, I need to direct users to the external URL pointing them to our app (in the example above, https://domain.com).

My use case was to change the logoLink on a site-wide level, so I've added support for including a URL at $site.themeConfig.logoLink. In the absence of this property, the logo link falls back to the $localePath (existing behavior).

I also thought it would be nice to add locale-specific logo links, so I first check for the presence of $themeLocaleConfig.logoLink, then $site.themeConfig.logoLink, then $localePath.

I've tested this manually but extensively. Since this is my first VuePress commit, I'm sure I'm missing something, so I'm definitely open to feedback.

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Docs
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)

You have tested in the following browsers: (Providing a detailed version will be better.)

All tests done on macOS 10.14

• Chrome 70.0.3538.77
• Firefox 63.0.3 (64-bit)
• Safari Version 12.0 (14606.1.36.1.9)
• Edge
• IE

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature
• Related documents have been updated
• Related tests have been updated (see below)

I didn't see any existing tests for the relevant code, but I'm happy to add / update those tests if you'd like.

[rajaraodv]

Thanks, @dylburger !

[flozero]

Hello @dylburger thank's for your pr i know it's been a while a create the pr. Sorry for that.

Can you please resolve the conflict ?

Thank's for your time !

[ulivz]

Conflict here