Update README.md

TINY Spelling/Readability ~documentation Changes
-added "a"
-changed "next" to "then" (moved "be)
-changed "not valid anymore" to "no longer valid"
-removed "allow to"
-changed "a" to "any" and "runner" to "runners"
-added "being"
-added "the tokens used in those tools should be updated to reflect"
-changed "new value" to "value of the new token"

doc/ci/runners/README.md

@@ -365,8 +365,8 @@ We're always looking for contributions that can mitigate these
 ### Resetting the registration token for a Project
 
 If you think that registration token for a Project was revealed, you should
-reset them. It's recommended because such token can be used to register another
-Runner to the Project. It may be next used to obtain the values of secret
+reset them. It's recommended because such a token can be used to register another
+Runner to the Project. It may then be used to obtain the values of secret
 variables or clone the project code, that normally may be unavailable for the
 attacker.
 
@@ -379,10 +379,10 @@ To reset the token:
 1. After the page is refreshed, expand the **Runners settings** section
    and check the registration token - it should be changed.
 
-From now on the old token is not valid anymore and will not allow to register
-a new Runner to the project. If you are using any tools to provision and
-register new Runners, you should now update the token that is used to the
-new value.
+From now on the old token is no longer valid and will not register
+any new Runners to the project. If you are using any tools to provision and
+register new Runners, the tokens used in those tools should be updated to reflect the
+value of the new token.
 
 ## Determining the IP address of a Runner