docs: remove docs completely, migrate them to zksync-era

[0xValera]

What ❔

There was still some documentation present in era-contracts repository.

We want to contain all of the documentation in zksync-era repository, so in this PR the documentation is removed completely from era-contracts repository.

Thezksync-era PR relevant to this one is here. We migrate missing pieces from here there in it.

Why ❔

Checklist

• PR title corresponds to the body of PR (we generate changelog entries from PRs).
• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.

[github-actions]

Coverage after merging vg/remove-docs-from-era-contracts into main will be

84.47%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
contracts/bridge
BridgeHelper.sol	85.71%	100%	100%	85%	31, 36, 41
BridgedStandardERC20.sol	82.14%	100%	92.31%	80.28%	120–121, 126–127, 139–140, 164, 205, 212, 219, 229–230, 63, 91
L1ERC20Bridge.sol	94%	100%	100%	93.02%	189, 208, 270
L1Nullifier.sol	83.33%	100%	86.21%	82.89%	114, 128–130, 160, 221, 224, 234, 237, 247, 250, 418–420, 424–425, 452, 518, 602, 614, 652, 654, 698, 710, 713, 715, 728, 741–742, 746–747, 767
contracts/bridge/asset-router
AssetRouterBase.sol	95.45%	100%	100%	94.44%	59, 87
L1AssetRouter.sol	88.33%	100%	88.89%	88.24%	208, 246, 262, 349, 360, 391, 430–431, 445, 476, 548, 60, 637, 648, 662, 667, 76, 84
contracts/bridge/interfaces
AssetHandlerModifiers.sol	75%	100%	100%	66.67%	13
contracts/bridge/ntv
L1NativeTokenVault.sol	84.82%	100%	88.24%	84.21%	144–150, 152, 220–221, 223, 234, 236, 240, 66
NativeTokenVault.sol	89.50%	100%	92%	89.10%	102, 234, 239, 256, 274, 279, 295, 314, 322, 488, 503, 531, 564–565, 569–570, 74
contracts/bridgehub
Bridgehub.sol	83.39%	100%	84.78%	83.15%	115, 123, 128–130, 137, 165–166, 182, 227–228, 236, 239, 248, 258, 271, 286, 315, 339, 342, 401, 417, 448, 528, 610, 708, 712, 716–717, 736, 739, 790, 793, 796, 831, 835, 838, 873–874, 878–879, 887–888, 892–893
CTMDeploymentTracker.sol	73.47%	100%	81.82%	71.05%	106, 110, 114, 139, 143–144, 32, 40, 65, 78–79
ChainAssetHandler.sol	77.94%	100%	80%	77.59%	125, 139, 142, 152, 197, 245–246, 250–251, 55, 62–63, 71
L2MessageVerification.sol	100%	100%	100%	100%
MessageRoot.sol	94.87%	100%	100%	93.85%	102, 136, 183, 193
contracts/common
ReentrancyGuard.sol	95%	100%	100%	94.12%	79
contracts/common/l2-helpers
L2ContractHelper.sol	94.34%	100%	100%	93.33%	102, 108, 112
SystemContractsCaller.sol	0%	100%	0%	0%	102, 114, 122–125, 128, 135–139, 141–142, 32–34, 37, 44–45, 47, 49, 51, 53, 66, 69, 72, 75, 78, 83, 89, 91, 93, 96, 98
contracts/common/libraries
DataEncoding.sol	85.11%	100%	100%	81.58%	109–110, 117–118, 163, 177, 45
DynamicIncrementalMerkle.sol	73.91%	100%	80%	73.17%	66–70, 72–74, 76–78
FullMerkle.sol	100%	100%	100%	100%
Merkle.sol	98.15%	100%	100%	97.96%	83
MessageHashing.sol	95.16%	100%	100%	94.64%	113, 77, 94
SemVer.sol	100%	100%	100%	100%
UncheckedMath.sol	100%	100%	100%	100%
UnsafeBytes.sol	100%	100%	100%	100%
contracts/governance
AccessControlRestriction.sol	100%	100%	100%	100%
ChainAdmin.sol	97.87%	100%	100%	97.30%	39
ChainAdminOwnable.sol	44.83%	100%	40%	45.83%	28, 38–40, 46–48, 57, 66, 77–79, 81
Governance.sol	100%	100%	100%	100%
L2ProxyAdminDeployer.sol	0%	100%	0%	0%	16–18, 20
PermanentRestriction.sol	88.80%	100%	100%	87.39%	103, 110–111, 199–200, 203–204, 207, 209–210, 239, 287, 309, 340
ServerNotifier.sol	93.10%	100%	100%	90.91%	55, 65
TransitionaryOwner.sol	0%	100%	0%	0%	16–17, 21–23
contracts/governance/restriction
Restriction.sol	100%	100%	100%	100%
RestrictionValidator.sol	100%	100%	100%	100%
contracts/state-transition
AccessControlEnumerablePerChainAddressUpgradeable.sol	98.15%	100%	100%	97.67%	179
ChainTypeManager.sol	86.07%	100%	84.62%	86.42%	111, 123, 129, 137–138, 248–251, 264–267, 282, 412, 474, 502, 509, 536, 584, 592–593
ValidatorTimelock.sol	89.25%	100%	77.78%	92%	120, 140, 163, 273, 292, 97
contracts/state-transition/chain-deps
DiamondInit.sol	92.68%	100%	100%	92.50%	50, 54, 58
DiamondProxy.sol	100%	100%	100%	100%
GatewayCTMDeployer.sol	0%	100%	0%	0%	166–167, 170, 172–174, 176, 178, 180, 188, 190, 192, 194, 196–197, 203, 215, 223, 226–227, 229, 235, 239–240, 248, 253–255, 262, 267–269, 282–285, 299, 304–309, 313, 326, 332, 334, 336–337, 341, 343–345, 353, 358, 362–363, 369, 375, 381, 388, 398, 404, 406, 416, 424, 438, 443, 448
contracts/state-transition/chain-deps/facets
Admin.sol	81.78%	100%	88%	81%	153–154, 171, 174, 178, 185–187, 190, 192, 195, 199–200, 204, 300, 303, 312, 315, 325, 332, 352, 366, 369, 376, 389, 392–393, 395–396, 398–399, 401, 404, 435, 439, 460, 466, 51
Executor.sol	88.22%	100%	100%	87.04%	133, 147, 154–156, 183, 221, 270, 279, 284, 287,

[zkzoomer]

If no docs are left here then we should remove the dead links CI workflow and add it to zksync-era instead