fixed fact about memory usage

doc/install/requirements.md

@@ -45,7 +45,7 @@ We recommend a processor with **4 cores**. At a minimum you need a processor wit
 ## Memory
-- 512MB is too little memory, GitLab will be very slow you will need 250MB of swap
+- 512MB is too little memory, GitLab will be very slow and you will need 250MB of swap
 - 768MB is the minimal memory size and supports up to 100 users
 - **1GB** is the **recommended** memory size and supports up to 1,000 users
 - 1.5GB supports up to 10,000 users