docs(user feedback): Add more about user feedback to API docs (#78233)

Adds documentation on how to list a project's user feedback if the
feedback is from the user feedback widget

Closes https://github.com/getsentry/sentry/issues/77941
Closes https://github.com/getsentry/sentry/issues/74113

---------

Co-authored-by: Michelle Zhang <56095982+michellewzhang@users.noreply.github.com>

api-docs/paths/events/project-issues.json

@@ -1,7 +1,7 @@
 {
   "get": {
     "tags": ["Events"],
-    "description": "Return a list of issues (groups) bound to a project.  All parameters are supplied as query string parameters. \n\n A default query of ``is:unresolved`` is applied. To return results with other statuses send an new query value (i.e. ``?query=`` for all results).\n\nThe ``statsPeriod`` parameter can be used to select the timeline stats which should be present. Possible values are: ``\"\"`` (disable),``\"24h\"`` (default), ``\"14d\"``",
+    "description": "Return a list of issues (groups) bound to a project.  All parameters are supplied as query string parameters. \n\n A default query of ``is:unresolved`` is applied. To return results with other statuses send an new query value (i.e. ``?query=`` for all results).\n\nThe ``statsPeriod`` parameter can be used to select the timeline stats which should be present. Possible values are: ``\"\"`` (disable),``\"24h\"`` (default), ``\"14d\"``\n\nUser feedback items from the [User Feedback Widget](https://docs.sentry.io/product/user-feedback/#user-feedback-widget) are built off the issue platform, so to return a list of user feedback items for a specific project, filter for `issue.category:feedback`.",
     "operationId": "List a Project's Issues",
     "parameters": [
       {

api-docs/paths/projects/user-feedback.json

@@ -1,7 +1,7 @@
 {
   "get": {
     "tags": ["Projects"],
-    "description": "Return a list of user feedback items within this project.\n\n*This list does not include submissions from the [User Feedback Widget](https://docs.sentry.io/product/user-feedback/#user-feedback-widget). This is because it is based on an older format called User Reports - read more [here](https://develop.sentry.dev/application/feedback-architecture/#user-reports).*",
+    "description": "Return a list of user feedback items within this project.\n\n*This list does not include submissions from the [User Feedback Widget](https://docs.sentry.io/product/user-feedback/#user-feedback-widget). This is because it is based on an older format called User Reports - read more [here](https://develop.sentry.dev/application/feedback-architecture/#user-reports). To return a list of user feedback items from the widget, please use the [issue API](https://docs.sentry.io/api/events/list-a-projects-issues/)* with the filter `issue.category:feedback`.*",
     "operationId": "List a Project's User Feedback",
     "parameters": [
       {