Update postcode guidance

[terrysimpson99]

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[aliuk2012]

This PR relates to this discussion

[amyhupe]

Hi @terrysimpson99 - thanks for your patience on this.

I've reviewed the content and I think it's mostly good but I want to suggest a couple of changes to the placement and structure.

I've done that as a separate PR (#918) as I didn't want to overwrite your version. Could you take a look? If you're happy, we can close this PR and merge the other one?

[terrysimpson99]

Hi @amyhupe I'm generally happy with the changes you've made. However, I wanted it to be clear that unnecessary characters should be ignored at the beginning, middle, and end. For example Royal Mail (https://www.royalmail.com/find-a-postcode) ignores undesirable characters in the middle and end but not at the beginning. If you understand what I mean and can encapsulate that, I'm fine with closing this PR and merging the other one. Alternatively, if you think there's a low risk of that happening, I'm fine too. I'll leave it to your judgement.

[amyhupe]

Hi @terrysimpson99 – I've now added "beginning, middle and end" as you asked. I'm going to close this PR now and get someone to approve the other one.