Allow the option to add notes to a supplier so we can store contractual terms/commercial guidance relating to a supplier within Linnworks

This is also useful for shipping information regarding a supplier. We have multiple suppliers for the same item but use them at different times. For example: supplier ABC is useless around xmas as they are too busy, so use another one instead - trying to remember this either in your head is okay when you have maybe a doz but lots of suppliers it quickly falls over - and the whole idea of linnworks is it should be 1 system to cope rather than it only doing so much and having to reference somewhere else for certain bits of information