Grammar fixes in entity_reference_revisions.info.yml and entity_reference_revisions.permissions.yml

Problem/Motivation

There are two grammar errors in the module:

1. In entity_reference_revisions.info.yml, the description uses "a" before a vowel sound: "Adds a Entity Reference field type with revision support."
2. In entity_reference_revisions.permissions.yml, the permission description contains awkward double "to": "Allow to access to the Entity Reference Revisions orphan deletion form."

Proposed resolution

1. entity_reference_revisions.info.yml

   -description: Adds a Entity Reference field type with revision support.
   +description: Adds an Entity Reference field type with revision support.
   

2. entity_reference_revisions.permissions.yml

   -description: 'Allow to access to the Entity Reference Revisions orphan deletion form.'
   +description: 'Allow access to the Entity Reference Revisions orphan deletion form.'