Updated https://forge.softwareheritage.org/source/opdocs/repository/master/

@zack has suggested to have a neutral document without HAL, but I think it is difficult to provide a guide about software deposit without
the specific explanation on how the HAL form works. That's why this version is not completely neutral, but with less information about HAL and HAL ids.

Also, for neutrality, I didn't add screen-shots for the HAL form.

It can be changed easily if more deposit features (new platform, a specific SWH form, sparse-deposit, metadata-deposit, etc...) will be made available.