[Pulumi] Tutorial updates (#16829)

* wip

* heading formatting

* wip

* wip

* wip

* updated worker script code

* updated route code

* updated code

* update tutorial flow

* lint check

* grammar

* grammar

* undo settings file change

* cf signup link

* update code to use esc projects

* Update src/content/docs/pulumi/tutorial/manage-secrets.mdx

Co-authored-by: Claire W <78226508+crwaters16@users.noreply.github.com>

* Update src/content/docs/pulumi/tutorial/manage-secrets.mdx

Co-authored-by: Claire W <78226508+crwaters16@users.noreply.github.com>

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Co-authored-by: diana esteves <diana@pulumi.com>
Co-authored-by: Claire W <78226508+crwaters16@users.noreply.github.com>