Styling fixes to guides

[aliabd]

Fixes code font on guides, adds previous and next guide buttons, and fixes some broken links.

Closes: #5490
Closes: #5491
Closes: #5492

[gradio-pr-bot]

🪼 branch checks and previews

•	Name	Status	URL
	Spaces	ready!	Spaces preview
	Website	ready!	Website preview
	Storybook	ready!	Storybook preview
	Visual tests	all good!	Build review
🦄	Changes	detected!	Details

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Install Gradio from this PR

pip install https://gradio-builds.s3.amazonaws.com/ef22873b312bb3724fec215899955ed9b83f2da6/gradio-3.44.4-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@ef22873b312bb3724fec215899955ed9b83f2da6#subdirectory=client/python"

[gradio-pr-bot]

🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
website	patch

• Maintainers can select this checkbox to manually select packages to update.

With the following changelog entry.

Styling fixes to guides

Maintainers or the PR author can modify the PR title to modify this entry.

Something isn't right?

• Maintainers can change the version label to modify the version bump.
• If the bot has failed to detect any changes, or if this pull request needs to update multiple packages to different versions or requires a more comprehensive changelog entry, maintainers can update the changelog file directly.

[aliabid94]

LGTM!