add new section and some tools

[Decuriosity]

User description

Hi, i believe that increasing conversions is something any startup needs, so I've added a new section and several tools.
All tools can be used for free (freemium)

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PR Type

Documentation

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Description

• Added a new section titled Web Experimentation.

• Listed four tools under the new section for experimentation.

• Tools include VWO, PostHog, OptimalUX, and Upflowy.

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Changes walkthrough 📝

	Relevant files
Documentation	README.md Introduced `Web Experimentation` section and tools              README.md Added a new section titled Web Experimentation. Listed four tools with links under the new section. +7/-0

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[qodo-code-review]

PR Reviewer Guide 🔍

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⏱️ Estimated effort to review: 1 🔵⚪⚪⚪⚪

🧪 No relevant tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Incorrect Link The PostHog link points to ProductHunt instead of the official PostHog website. This should be updated to https://posthog.com - PostHog - https://www.producthunt.com/

[qodo-code-review]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
General	✅ Fix incorrect external URL Suggestion Impact: Changed PostHog URL from ProductHunt to official PostHog website code diff: -- PostHog - https://www.producthunt.com/ +- PostHog - https://posthog.com/ The PostHog link points to ProductHunt instead of the official PostHog website. Update it to the correct URL. README.md [223] -- PostHog - https://www.producthunt.com/ +- PostHog - https://posthog.com/ [Suggestion has been applied] Suggestion importance[1-10]: 8 __ Why: The suggestion correctly identifies and fixes an incorrect URL that points to ProductHunt instead of PostHog's official website, which is important for user navigation and resource accuracy.	Medium
No more code suggestions

[Decuriosity]

I thought about adding this section to Tech, but CRO is more about marketing after all