Training page in the top nav (#19214)

* Create new page and add to top nav

Signed-off-by: Celeste Horgan <celeste@cncf.io>

* The basics

Signed-off-by: Celeste Horgan <celeste@cncf.io>

* A bit of inline css

Signed-off-by: Celeste Horgan <celeste@cncf.io>

* Fix CSS

Signed-off-by: Celeste Horgan <celeste@cncf.io>

* Fix link + Add to bottom row

Signed-off-by: Celeste Horgan <celeste@cncf.io>

* Address feedback in PR

* Address feedback from elsewhere

* Fix button alignment

* Add training partners

* Simplify css

* Apply suggestions from review

Co-Authored-By: Zach Corleissen <zacharysarah@users.noreply.github.com>

* Fix landscape + text block widths

Co-authored-by: Zach Corleissen <zacharysarah@users.noreply.github.com>

static/css/gridpage.css

@@ -25,7 +25,7 @@
 
 
 .gridPage p {
-    color: rgb(26,26,26) !important;
+    color: rgb(26,26,26);
     margin-left: 0 !important;
     padding-left: 0 !important;
     font-weight: 300 !important;