Update grammar date in example on #writing-style-guidelines

Description

List Item 6 from Writing Style Guidelines states:

Always use ISO dates in all writing and legal documents since other formats lead to online confusion. Use yyyy-mm-dd, for example 2015-04-13, and never 04-13-2015, 13-04-2015, 2015/04/13, nor March 4, 2013. Even if you use a unambiguous alternative format it is still harder to search for a date, sort on a date, and for other team members to know we use the iso standard. For quarters use 2018-Q3.

All the examples dates are 2015/04/13 except March 4th, 2013, which was confusing to read.

Checklist when modifying an existing page:

  • What is the goal of changing the page?
  • What metrics are we trying to affect?
  • How will we decide if the change was successful or not?
  • Would we revert the changes if we decided that it was not a success?
  • Make sure events are reflected in Google Analytics/Marketo if the page is changed
  • Make sure redirection is done if we change the page so email newsletters do not contain dead link

Proposal

Modify the statement to show the wrong date April 13, 2015 in alignment with other wrong dates.

Always use ISO dates in all writing and legal documents since other formats lead to online confusion. Use yyyy-mm-dd, for example 2015-04-13, and never 04-13-2015, 13-04-2015, 2015/04/13, nor April 13, 2015. Even if you use an unambiguous alternative format it is still harder to search for a date, sort on a date, and for other team members to know we use the iso standard. For quarters use 2018-Q3.

Links / references

/cc @gl-docsteam

Edited by Casey Burnett