Update API-design-guidelines.md-with-wildcard-scopes-icm-agreement

[shilpa-padgaonkar]

What type of PR is this?

Add one of the following kinds:

• documentation

What this PR does / why we need it:

This PR includes the following changes:

• Documents the agreement in ICM on wildcard scopes discussed under the issue -(https://github.com/camaraproject/IdentityAndConsentManagement/issues/95) into the design guidelines to ensure completeness of the doc,

• The explicit subscriptions related scope changes were documented in the PR https://github.com/camaraproject/Commonalities/pull/177 . The scope naming is described in 2 sections in the design doc - 10.2 and 11.6.1. The earlier PR only updated section 10.2 (b). This PR adds the needed content also in section 11.6.1

Which issue(s) this PR fixes:

Fixes #184

Special notes for reviewers:

Changelog input

 release-note

Additional documentation

This section can be blank.

docs

[shilpa-padgaonkar]

@AxelNennker and @jpengar Could you kindly check if the section "API-level scopes" reflects correctly the agreement made in https://github.com/camaraproject/IdentityAndConsentManagement/issues/95

@PedroDiez and @bigludo7 : I have simply duplicated the content of https://github.com/camaraproject/Commonalities/pull/177 into the section 11.6.1 to ensure consistency. Could you kindly take a look?