Add equity to careers page (#759)

Add it to the benefits list, as it is an important part of our compensation package.

Author: brikis98

pages/careers/_human-friendly.html

@@ -20,6 +20,7 @@ <h3>Benefits</h3>
     <p>Our benefits reflect our values. We believe compensation should be fair, transparent, and generous. We hire Grunts in many countries, so some details may vary.</p>
     <ul>
       <li><strong>Location Independent, Above-Market Salary.</strong> To reduce bias and increase transparency, we compute all salaries <a href="https://blog.gruntwork.io/how-we-hire-at-gruntwork-42193d583e24">using formulas</a>. The formula factors in your title and uses a multiplier to produce a result that's above market for that title. Our salaries are location independent.</li>
+      <li><strong>Equity.</strong> To reduce bias and increase transparency, we compute all stock grants <a href="https://blog.gruntwork.io/how-we-built-a-distributed-self-funded-family-friendly-profitable-startup-93635feb5ace">using formulas</a>. The formula for equity factors in your title and your employee number. Moreover, we offer a Change in Control Bonus Plan, inspired by <a href="https://medium.com/detour-dot-com/introducing-progressive-equity-f424a51ee3a4">Progressive Equity</a>, where if there is a large exit event, employees end up with a larger portion of the proceeds (rather than the founders hogging it all).</li>
       <li><strong>Profit-Sharing Bonus.</strong> We set aside a pot of money at the end of each year based on profits and distribute bonuses according to a formula that uses as inputs your level within the company and the length of your tenure at the company.</li>
       <li><strong>Hardware Budget.</strong> We'll buy you a brand new 16" Apple MacBook Pro (or other computer of your choosing of equivalent value) upon joining. It will be owned by you, not the company.</li>
       <li><strong>Personal Budget.</strong> We'll give you a personal budget of $1,000 USD per month to spend on your workspace (e.g., a co-working space), health (e.g., gym, yoga), time (e.g., babysitter), and/or learning (e.g., books, courses).</li>