Fix linting errors in notifications.md

Fix linting errors in https://docs.gitlab.com/ee/user/profile/notifications.html

Related: #284446 (closed)

16:5     error  Avoid using future tense: "will receive". Use present tense instead.   gitlab.FutureTense
21:38    error  Avoid using future tense: "will receive". Use present tense instead.   gitlab.FutureTense
53:50    error  Avoid using future tense: "will be". Use present tense instead.        gitlab.FutureTense
141:7    error  Avoid using future tense: "will be". Use present tense instead.        gitlab.FutureTense
161:46   error  Avoid using future tense: "will be". Use present tense instead.        gitlab.FutureTense
196:193  error  Avoid using future tense: "will be". Use present tense instead.        gitlab.FutureTense
202:24   error  Avoid using future tense: "will be". Use present tense instead.        gitlab.FutureTense
205:5    error  Avoid using future tense: "won't receive". Use present tense instead.  gitlab.FutureTense
206:48   error  Avoid using future tense: "will only". Use present tense instead.      gitlab.FutureTense
210:74   error  Avoid using future tense: "will be". Use present tense instead.        gitlab.FutureTense
212:16   error  Avoid using future tense: "will also". Use present tense instead.      gitlab.FutureTense
255:19   error  Avoid using future tense: "will have". Use present tense instead.      gitlab.FutureTense

If you'd like to work on this issue, mention @msedlakjakubowski in a comment. Then, in your merge request's description, paste this issue's URL so they become linked.