DOC: fix URLs, formatting and typos
"## Development tools" is not formatted correctly here: https://pandas.pydata.org/community/ecosystem.html
![Screenshot 2022-02-10 10 22 42](https://user-images.githubusercontent.com/23830955/153439086-c356f348-0e12-4888-9f46-a8729eab8bc7.png)


> Thanks @partev - btw, if you have many more changes like these, it's OK to group them together into the same PR
> 

yes, please don't fill up the PRs with a number of one line typos fixes. 

It is probably better to close the other PRs and include them all here. Thx > > Thanks @partev - btw, if you have many more changes like these, it's OK to group them together into the same PR
> 
> yes, please don't fill up the PRs with a number of one line typos fixes.
> 
> It is probably better to close the other PRs and include them all here. Thx

ok, I will combine them here. thanks @partev  @meeseeksdev backport 1.4.x Something went wrong ... Please have a look at my logs.