misc: optimize showcase images

[lex111]

Motivation

Reducing size of sites screenshots in the showcase, which potentially should speed up build site / page load and just facilitate work for ideal-image plugin.

Have you read the Contributing Guidelines on pull requests?

Yes

Test Plan

Preview

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.)

[netlify]

✔️ [V1]

🔨 Explore the source changes: c389735

🔍 Inspect the deploy log: https://app.netlify.com/sites/docusaurus-1/deploys/60b90d5468a7280008dff54f

😎 Browse the preview: https://deploy-preview-4901--docusaurus-1.netlify.app

[netlify]

✔️ [V2]

🔨 Explore the source changes: c389735

🔍 Inspect the deploy log: https://app.netlify.com/sites/docusaurus-2/deploys/60b90d549b6588000761f85c

😎 Browse the preview: https://deploy-preview-4901--docusaurus-2.netlify.app

[github-actions]

⚡️ Lighthouse report for the changes in this PR:

Category	Score
🟠 Performance	62
🟢 Accessibility	97
🟢 Best practices	100
🟢 SEO	100
🟢 PWA	95

Lighthouse ran on https://deploy-preview-4901--docusaurus-2.netlify.app/

[github-actions]

Size Change: 0 B

Total Size: 621 kB

ℹ️ View Unchanged

Filename	Size	Change
website/build/assets/css/styles.********.css	88.3 kB	0 B
website/build/assets/js/main.********.js	443 kB	0 B
website/build/blog/2017/12/14/introducing-docusaurus/index.html	62.3 kB	0 B
website/build/docs/introduction/index.html	235 B	0 B
website/build/index.html	27.1 kB	0 B

_{compressed-size-action}

[slorber]

Thanks, LGTM 👍

Also wanted to do that. Maybe you could add a node script so that we could run this compression again from time to time?

[lex111]

Used this package for this, and "optimizt `find src/data/showcase -type f -name '*.png'`" command in particular. Perhaps it makes sense to create separate GitHub action that will automatically optimize images in new PRs?

[slorber]

Thanks, just keeping the command in git may be enough for now, we won't run that often, but if you find a way to automate this, why not as long as it's not run on every PR