[docs] Fix grammar (#19062)

README.md

@@ -50,7 +50,7 @@ Please note that `@next` will only point to pre-releases; to get the latest stab
 
 *3/3 slots available*
 
-Diamond Sponsors are those who have pledged $2,000/month and more to Material-UI.
+Diamond Sponsors are those who have pledged $2,000/month or more to Material-UI.
 Please contact us at [email protected] to subscribe to this tier.
 
 ### Gold 🏆
@@ -68,7 +68,7 @@ via [OpenCollective](https://opencollective.com/material-ui)
   <a data-ga-event-category="sponsors" data-ga-event-action="logo" data-ga-event-label="callemall" href="https://www.call-em-all.com" rel="noopener sponsored" target="_blank" style="margin-right: 16px;"><img src="https://images.opencollective.com/proxy/images?src=https%3A%2F%2Fopencollective-production.s3-us-west-1.amazonaws.com%2Ff4053300-e0ea-11e7-acf0-0fa7c0509f4e.png&height=100" alt="call-em-all" title="The easy way to message your group" width="100" loading="lazy"></a>
 </p>
 
-Gold Sponsors are those who have pledged $500/month and more to Material-UI.
+Gold Sponsors are those who have pledged $500/month or more to Material-UI.
 
 ### There is more!
 

docs/src/modules/components/backers.md

@@ -6,7 +6,7 @@ The core of Material-UI is a [crowd-funded](/discover-more/backers/) open-source
 
 *3/3 slots available*
 
-Diamond Sponsors are those who have pledged $2,000/month and more to Material-UI.
+Diamond Sponsors are those who have pledged $2,000/month or more to Material-UI.
 Please contact us at [email protected] to subscribe to this tier.
 
 ### Gold 🏆
@@ -24,7 +24,7 @@ via [OpenCollective](https://opencollective.com/material-ui)
   <a data-ga-event-category="sponsors" data-ga-event-action="logo" data-ga-event-label="callemall" href="https://www.call-em-all.com" rel="noopener sponsored" target="_blank" style="margin-right: 16px;"><img src="https://images.opencollective.com/proxy/images?src=https%3A%2F%2Fopencollective-production.s3-us-west-1.amazonaws.com%2Ff4053300-e0ea-11e7-acf0-0fa7c0509f4e.png&height=100" alt="call-em-all" title="The easy way to message your group" width="100" loading="lazy"></a>
 </p>
 
-Gold Sponsors are those who have pledged $500/month and more to Material-UI.
+Gold Sponsors are those who have pledged $500/month or more to Material-UI.
 
 ### There are more!
 

docs/src/pages/discover-more/backers/backers.md

@@ -10,7 +10,7 @@ The core of Material-UI is a crowd-funded open-source project, licensed under th
 
 *3/3 slots available*
 
-Diamond Sponsors are those who have pledged $2,000/month and more to Material-UI.
+Diamond Sponsors are those who have pledged $2,000/month or more to Material-UI.
 Please contact us at [email protected] to subscribe to this tier.
 
 ### Gold 🏆
@@ -28,7 +28,7 @@ via [OpenCollective](https://opencollective.com/material-ui)
   <a data-ga-event-category="sponsors" data-ga-event-action="logo" data-ga-event-label="callemall" href="https://www.call-em-all.com" rel="noopener sponsored" target="_blank" style="margin-right: 16px;"><img src="https://images.opencollective.com/proxy/images?src=https%3A%2F%2Fopencollective-production.s3-us-west-1.amazonaws.com%2Ff4053300-e0ea-11e7-acf0-0fa7c0509f4e.png&height=100" alt="call-em-all" title="The easy way to message your group" width="100" loading="lazy" /></a>
 </p>
 
-Gold Sponsors are those who have pledged $500/month and more to Material-UI.
+Gold Sponsors are those who have pledged $500/month or more to Material-UI.
 
 ### Silver