add example bundle with sensitive data

[VinozzZ]

This PR adds an example bundle that contains sensitive data so that we can demonstrate how to work with such bundles in Porter

[carolynvs]

Can you provide steps for what they should configure (it's okay to link to the quickstart or existing doc) and then include a section that has them try out the bundle?

You can look at https://github.com/getporter/examples/tree/main/otel-jaeger for the amount of detail that we want to include in the example readmes. Essentially someone should be able to figure out how to configure porter and then run the example bundle.

[carolynvs]

Also I have started to keep an index of all the examples on the README, so make sure to add yours to the learn section.

[carolynvs]

I think the reference below doesn't match where the bundle will end up being published?

Suggested change

	porter install --reference ghcr.io/getporter/examples/porter-sensitive-data:v0.1.0
	porter install --reference ghcr.io/getporter/examples/sensitive-data:v0.1.0

[carolynvs]

When I tried to run the install command without any additional flags the installation failed because one of the parameters is required and does not have a default. Can you update the instructions to include the full command including all required arguments?

$ porter install
Building bundle ===>
Defaulting the type of output name to file
Copying porter runtime ===>
Copying mixins ===>
Copying mixin exec ===>

Generating Dockerfile =======>

Writing Dockerfile =======>
Building invocation image
Checking database schema
Selected configured plugin	{"plugin-key": "mongodb"}
Connecting to plugin	{"plugin-command": "/Users/carolynvs/.porter/porter plugin run storage.porter.mongodb"}
starting plugin
plugin started
waiting for RPC address
using plugin
plugin address
Initializing installation collection indices
Initializing parameter collection indices
Initializing credentials collection indices
parameter "password" is required
received EOF, stopping recv loop
plugin process exited
plugin exited

[carolynvs]

Perfect, thanks for adding this example!