Rename README to README.md

[CLHRAE]

I know, I know, who cares? I do. This and cw-proposal-single were named README, whereas every other contract was named README.md.

[github-actions]

Cosm-Orc Gas Usage

No gas diff larger than 0.5%

Raw Report for d2180d6

Contract	Op Name	Gas Used	Gas Wanted	File
cw20_base	Execute__exc_stake_stake_tokens	234578	319223	ci/integration_tests/src/tests/cw20_stake_test.rs:76
cw20_base	Store__Store	34543940	51791270	ci/integration_tests/src/helpers/chain.rs:98
cw_core	Instantiate__exc_stake_create_dao	980056	1445481	ci/integration_tests/src/helpers/helper.rs:89
cw_core	Execute__exc_admin_msgs_pause_dao	194393	267078	ci/integration_tests/src/tests/cw_core_test.rs:76
cw_core	Instantiate__exc_admin_msgs_create_dao	980080	1445517	ci/integration_tests/src/helpers/helper.rs:89
cw_core	Instantiate__exc_admin_msgs_create_dao_with_admin	981130	1447092	ci/integration_tests/src/helpers/helper.rs:89
cw_core	Store__Store	45362880	68019680	ci/integration_tests/src/helpers/chain.rs:98
cw_core	Instantiate__inst_dao_no_admin	980080	1445517	ci/integration_tests/src/helpers/helper.rs:89
cw_core	Instantiate__inst_admin_create_dao	981130	1447092	ci/integration_tests/src/helpers/helper.rs:89
cw_core	Execute__exc_items_rm	192600	264389	ci/integration_tests/src/tests/cw_core_test.rs:171
cw_core	Execute__exc_items_set	194267	266889	ci/integration_tests/src/tests/cw_core_test.rs:136
cw_core	Instantiate__exc_items_create_dao	981130	1447092	ci/integration_tests/src/helpers/helper.rs:89
cw20_stake	Store__Store	28643210	42940175	ci/integration_tests/src/helpers/chain.rs:98
cw20_staked_balance_voting	Store__Store	29117530	43651655	ci/integration_tests/src/helpers/chain.rs:98
cw4_group	Store__Store	22594860	33867650	ci/integration_tests/src/helpers/chain.rs:98
cw4_voting	Store__Store	21510590	32241245	ci/integration_tests/src/helpers/chain.rs:98
cw721_stake	Store__Store	30723310	46060325	ci/integration_tests/src/helpers/chain.rs:98
cw_admin_factory	Store__Store	16046340	24044870	ci/integration_tests/src/helpers/chain.rs:98
cw_named_groups	Store__Store	19289580	28909730	ci/integration_tests/src/helpers/chain.rs:98
cw_names_registry	Store__Store	20949215	31399511	ci/integration_tests/src/helpers/chain.rs:98
cw_native_staked_balance_voting	Store__Store	24081730	36097955	ci/integration_tests/src/helpers/chain.rs:98
cw_proposal_multiple	Store__Store	50606800	75885560	ci/integration_tests/src/helpers/chain.rs:98
cw_proposal_single	Store__Store	51120610	76656275	ci/integration_tests/src/helpers/chain.rs:98
cw_staking_denom_voting	Store__Store	17199360	25774400	ci/integration_tests/src/helpers/chain.rs:98
cw_token_swap	Store__Store	19083660	28600850	ci/integration_tests/src/helpers/chain.rs:98
stake_cw20_external_rewards	Store__Store	25148730	37698455	ci/integration_tests/src/helpers/chain.rs:98
stake_cw20_reward_distributor	Store__Store	19137230	28681205	ci/integration_tests/src/helpers/chain.rs:98

[0xekez]

it's an obscure aesthetic preference, but less readable. thank you :)