feat: add date letters to en.json

[KiGamji]

Type

Cosmetic

Manager Branch

Flutter

Issue

Currently, there is a string in en.json -> latestCommitCard -> timeagoLabel thats called "{time} ago". But the dates, fetched from github is not translated, so translated to, for example, russian string "{time} назад" will look like "1d назад".

Feature

Add date letters to en.json, such as "d", "s", "m", "w" etc.

Motivation

Because it's wrong to use such date ago translation format, and it looks so weird when you use different from english l10n.

Additional context

No response

[ponces]

timeago package has also a feature for translations. We can look on improving this to use them. Thanks.