Add boundaries to countries README.md and boundaries source and boundaries disclamer to png images.

[nastasi-oq]

This PR introduce

• boundaries souce and boundaries disclamer to the country profiles images
• a Boundaries section to countries README.md file with info about boundaries (data source, publisher and a link) and the same boundaries disclamer added to country profiles images
• Bulgaria, Lithuania, Kenya, Tanzania countries have been replaced because changed after an update of all mosaic regions repositories (all other countries remains the same).

[raoanirudh]

• Russia: Adm1 names in Loss by Region bar chart are cutoff

Apart from that, LGTM!

[pslh]

Other than Russia ADM1 name issue signaled by Anirudh, LGTM

[nastasi-oq]

Enhanced LOSS BY REGION chart replacing horizontal labels with 45° labels and changing dynamically the font size depending on the number of rows of the chart.
The graphical part of the chart benefits of the changes because became generally bigger.
There are fiew countries where the X axis is not aligned with corresponding X axis of LOSS CURVES chart (take a look to Venuezuela profile to see an example).
Russia now works.
Let me know if this new approach is acceptable.