dod.amsr() docs need more detail on history and oce connection

[dankelley]

I want to add

• [ ] more on the history
• [ ] an example plot
• [ ] info on the connection with oce

I'll need so sync some things up with oce::download.amsr() but the good thing is that the latter is totally broken now (with the new file-system layout on the server) and so I don't have to worry too much about trying to make dod work with both the CRAN oce and the github oce.

[dankelley]

In "main" commit 484fd3beb5a74dbec2871993fd62a64e62efa51c I now have an example. It is set not to run, because it involves downloading a 12Mb file. I suppose CRAN might allow that, if I make a temporary directory, but I don't quite see the point, because this example is just a stop-gap measure, until I update oce to plot the new type of amsr data file.

PS. the example makes like below. Fairly windy down south :-)