[docs] refactoring of docs

Makefile

bitshares/account.py

bitshares/amount.py

bitshares/asset.py

bitshares/bitshares.py

bitshares/block.py

bitshares/blockchain.py

bitshares/dex.py

bitshares/market.py

bitshares/memo.py

bitshares/price.py

bitshares/transactionbuilder.py

bitshares/wallet.py

bitsharesapi/bitsharesnoderpc.py

docs/Makefile

docs/account.rst

docs/amount.rst

docs/asset.rst

docs/base58.rst

docs/bip38.rst