x/website: Mention specifically that minor version is not allowed in Go directives

[sagar-jadhav]

I was trying out Go modules and find out that If I specify 1.15.4 instead of 1.15 my build failed with the following error:

invalid go version '1.15.4': must match format 1.23

I referred to this documentation https://golang.org/ref/mod#go-mod-file-go. I think it will be better If we also recommend not to use the minor version or give examples of the wrong values for better understanding.

[ALTree]

It does say

a positive integer followed by a dot and a non-negative integer (for example, 1.9, 1.14)

which I think is pretty clear on the allowed format "an integer, a dot, another integer, that's it". The error you received on the bad version string is also very easy to understand:

1.15.4: must match format 1.23

I'm not sure we need to make the explanation longer, and in general "bad" examples (like "DO NOT DO THIS, IT'S INVALID: 1.14.7) are not great (you need to make it really clear that it's a bad example, which is often verbose, only presenting valid examples is generally clearer and preferable, IMO).

[sagar-jadhav]

@ALTree I got your point. Thanks.

[ALTree]

Closing here then.