docs(v2): Fix link to slash introduction svg

[SamChou19815]

Motivation

According to #4126, we shouldn't be using baseUrl for the images in markdowns. It also broke the image on the old versioned docs (You can also see this on https://v2.docusaurus.io/docs/):

I replaced the img tag with markdown image link, to make it consistent with the latest docs.

Have you read the Contributing Guidelines on pull requests?

Yes

Test Plan

Now fixed:

Related PRs

(If this PR adds or changes functionality, please take some time to update the docs at https://github.com/facebook/docusaurus, and link to your PR here.)

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Size Change: +15 B (0%)

Total Size: 158 kB

ℹ️ View Unchanged

Filename	Size	Change
website/build/assets/css/styles.********.css	17.6 kB	0 B
website/build/assets/js/main.********.js	111 kB	+14 B (0%)
website/build/blog/2017/12/14/introducing-docusaurus/index.html	21.7 kB	-1 B (0%)
website/build/docs/introduction/index.html	180 B	0 B
website/build/index.html	6.95 kB	+2 B (0%)

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Deploy preview for docusaurus-2 ready!

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⚡️ Lighthouse report for the changes in this PR:

Category	Score
🟠 Performance	89
🟢 Accessibility	96
🟢 Best practices	100
🟢 SEO	100
🟢 PWA	95

Lighthouse ran on https://deploy-preview-4229--docusaurus-2.netlify.app/classic/

[slorber]

Thanks @SamChou19815 !

I was really surprised by this problem as it worked before and I didn't change the actual code, just the doc.

Found out the issue: I enabled the English language on Crowdin by mistake, so we upload sources and redownload them as English translations.

Crowdin is yet very good to handle JSX (really hope they'll add mdx support!) and somehow convert some JSX attributes as plain strings:

So I'll still merge this PR, and also disabled the English language on Crowdin