Restructure of pester test layout

This restructuring moves tests to a directory name which matches the module
in which the cmdlet resides which should improve the discoverability of a
specific test.
For tests which are not about cmdlets in a module, new directories have been
created to make those tests easier to find as well

test/powershell/SDK/CmdletExample.Tests.ps1

@@ -0,0 +1,9 @@
+try {
+    $enlistmentRoot = git rev-parse --show-toplevel
+
+    $docLocation = [io.path]::Combine($enlistmentRoot, "docs","cmdlet-example")
+    Push-Location $docLocation
+    ./SendGreeting.Tests.ps1
+} finally {
+    Pop-Location
+}