remove (some) Trello references (#1465)

.config/mkdocs.yml

@@ -101,7 +101,6 @@ nav:
           - common-practices-tools/software-and-support/mural.md
           - common-practices-tools/software-and-support/sauce-labs.md
           - common-practices-tools/software-and-support/slack.md
-          - common-practices-tools/software-and-support/trello.md
           - common-practices-tools/software-and-support/zoom.md
       - common-practices-tools/telephone.md
   - Practice areas:

.config/redirects.yml

@@ -190,9 +190,6 @@
 - from_url: /common-practices-tools/software-and-support/text-editors/
   to_url: /practice-areas/engineering/text-editors-ides/
   type: page
-- from_url: /050-how-we-work/tools/trello/
-  to_url: /common-practices-tools/software-and-support/trello/
-  type: page
 - from_url: /050-how-we-work/tools/zoom/
   to_url: /common-practices-tools/software-and-support/zoom/
   type: page

common-practices-tools/software-and-support/markdown.md

@@ -6,7 +6,7 @@ title: Markdown
 
 ## What is it?
 
-Markdown is a lightweight markup language with plain text formatting syntax. It's relatively easy to learn and use, and displays well on GitHub; versions of it are also used in Slack, Trello and Jira, among others. This documentation is written using it. It's worth learning, if you haven't already.
+Markdown is a lightweight markup language with plain text formatting syntax. It's relatively easy to learn and use, and displays well on GitHub; versions of it are also used in Slack and Jira, among others. This documentation is written using it. It's worth learning, if you haven't already.
 
 There's a great tutorial [on the Commonmark website](http://commonmark.org/help/tutorial/).
 
@@ -15,7 +15,6 @@ There's a great tutorial [on the Commonmark website](http://commonmark.org/help/
 -   [markdowntutorial.com](http://markdowntutorial.com/)
 -   [GitHub markdown cheatsheet](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet)
 -   [MarkdownLivePreview.com](http://markdownlivepreview.com/)
--   [Trello markdown cheatsheet](http://help.trello.com/article/821-using-markdown-in-trello)
 -   [Jira markdown cheatsheet](https://confluence.atlassian.com/bitbucketserver/markdown-syntax-guide-776639995.html)
 -   [Slack markdown cheatsheet](https://get.slack.help/hc/en-us/articles/202288908-Format-your-messages)
 

company-policies/new-hire-orientation/bookmarks.md

@@ -25,7 +25,6 @@ Links to websites we use regularly.
 -   [Google Hangouts](https://hangouts.google.com/)
 -   [Slack](https://civicactions.slack.com)
 -   [Unanet](https://civicactions.unanet.biz)
--   [Trello](https://trello.com/)
 -   [Zoom](https://zoom.us/)
 -   [Invision](https://www.invisionapp.com/home)
 -   Atlassian's Jira for ticket management