add test JWT token generation instructions

backend/app/rest/api/rest_test.go

@@ -37,6 +37,9 @@ import (
 	"github.com/umputun/remark42/backend/app/store/service"
 )
 
+// To generate a token, enter one of the tokens here into https://jwt.io, change the secret to one you're using in your test
+// ("secret" in case of startupT), and alter the fields you want to be changed.
+
 var devToken = `eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJyZW1hcms0MiIsImV4cCI6Mzc4OTE5MTgyMiwianRpIjoicmFuZG9tIGlkIiwiaXNzIjoicmVtYXJrNDIiLCJuYmYiOjE1MjE4ODQyMjIsInVzZXIiOnsibmFtZSI6ImRldmVsb3BlciBvbmUiLCJpZCI6ImRldiIsInBpY3R1cmUiOiJodHRwOi8vZXhhbXBsZS5jb20vcGljLnBuZyIsImlwIjoiMTI3LjAuMC4xIiwiZW1haWwiOiJtZUBleGFtcGxlLmNvbSJ9fQ.aKUAXiZxXypgV7m1wEOgUcyPOvUDXHDi3A06YWKbcLg`
 
 var anonToken = `eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJyZW1hcms0MiIsImV4cCI6Mzc4OTE5MTgyMiwianRpIjoicmFuZG9tIGlkIiwiaXNzIjoicmVtYXJrNDIiLCJuYmYiOjE1MjE4ODQyMjIsInVzZXIiOnsibmFtZSI6ImFub255bW91cyB0ZXN0IHVzZXIiLCJpZCI6ImFub255bW91c190ZXN0X3VzZXIiLCJwaWN0dXJlIjoiaHR0cDovL2V4YW1wbGUuY29tL3BpYy5wbmciLCJpcCI6IjEyNy4wLjAuMSIsImVtYWlsIjoiYW5vbkBleGFtcGxlLmNvbSJ9fQ.gAae2WMxZNZE5ebVboptPEyQ7Nk6EQxciNnGJ_mPOuU`