use lowercase URLs

README.md

 # www-gitlab-com
-This is the source for the https://about.gitlab.com/ site.
+This is the source for the https://about.gitlab.com/ site. For a guide on how to start editing the website using git, see the [handbook page on that topic](https://about.gitlab.com/handbook/git-page-update).
 ## Local development
@@ -126,7 +126,7 @@ instructions.
 Edit [`data/team.yml`](./data/team.yml) and add a new entry for yourself (or
 update the placeholder with your initials).
-Images should be uploaded to [`source/images/team`](./source/images/team).
+Images should be square, and should be uploaded to [`source/images/team`](./source/images/team).
 ### Adding a pet to the team pets page

source/handbook/communication/index.html.md

@@ -239,6 +239,7 @@ doesn't unnecessarily appear on other people's calendars.
 1. If you have multiple points in a comment or email, please number them to make replies easier.
 1. When you reference an issue, merge request, comment, commit, page, doc, etc. and you have the URL available please paste that in.
 1. In URLs, always prefer hyphens to underscores.
+1. In URLs, always use lowercase.
 1. The community include users, contributors, core team members, customers, people working for GitLab Inc., and friends of GitLab. If you want to refer to 'people not working for GitLab Inc.' just say that and don't use the word community. If you want to refer to people working for GitLab Inc. you can also use 'the GitLab Inc. team' but don't use the 'GitLab Inc. employees'.
 1. When we refer to the GitLab community excluding GitLabbers please say 'wider community' instead of 'community'.
 1. All people working for GitLab the company are the [GitLab team](https://about.gitlab.com/team/), we also have the [Core team](https://about.gitlab.com/core-team/) that consists of volunteers.

source/handbook/handbook-usage/index.html.md

@@ -27,5 +27,6 @@ After it is merged you can talk about it during the team call if applicable. You
 1. When communicating something always include a link to the relevant (and up to date) part of the **handbook** instead of including the text in the email/chat/etc. You can remind other people of this by asking "Can you please link to the relevant part of the handbook?"
 1. If you copy content please remove it at the origin place and replace it with a link to the new content. Duplicate content leads to updating it in the wrong place, keep it [DRY](https://en.wikipedia.org/wiki/Don%27t_repeat_yourself).
 1. If someone inside or outside GitLab makes a good suggestion invite them to add it to the handbook. Send the person the url of the relevant page and section and offer to do it for them if they can't. Having them make and send it will make the change and review reflect their knowledge.
+1. Learn how to edit the [handbook using git](/handbook/git-page-update). Please read through the [Writing Style Guidelines](https://about.gitlab.com/handbook/communication/#writing-style-guidelines) before contributing.
 Many things are documented in the handbook, but it will mostly be read by GitLabbers. If something concerns users of GitLab, it should be documented in the [GitLab documentation](http://doc.gitlab.com/), the [GitLab Development Kit (GDK)](https://gitlab.com/gitlab-org/gitlab-development-kit), the [CONTRIBUTING file](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md) or the [PROCESS file](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/PROCESS.md).