add ian to team handbook

[ivanagas]

add myself (ian vanagas) to team handbook

Changes

Add myself to team handbook.

Will wait for pixel headshot from Lottie to merge.

Checklist

• [ ] Titles are in sentence case
• [ ] Feature names are in sentence case too
• [ x] Words are spelled using American English
• [ ] I have checked out our style guide

[netlify[bot]]

👷 Deploy request for posthog accepted.

Name	Link
🔨 Latest commit	78f905e5d00ac7cf51aec5d9f8929571840bb1f9
🔍 Latest deploy log	https://app.netlify.com/sites/posthog/deploys/634015177647d60008f50394

[joethreepwood]

@lottiecoxon when you have a headshot for Ian it can probably just join this PR.