Update routing.rst

Added a note to provide extra guidance when naming routes
Applied comments
minor #3857 Added little bit information about the route name (WouterJ)

This PR was merged into the 2.3 branch.

Discussion
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Added little bit information about the route name

This PR replaces #3263

| Q   | A
| --- | ---
| Doc fix? | no
| New docs? | yes
| Applies to | all
| Fixed tickets | -

Commits
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90e654b Applied comments
66d60d2 Update routing.rst