chore: prepare Cosmovisor v0.1.0 release (#9868)

## Description

Release Notes + Changelog


---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [x] added `!` to the type prefix if API or client breaking change
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [x] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [x] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [x] added a changelog entry to `CHANGELOG.md`
- [x] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [x] updated the relevant documentation or specification
- [x] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

cosmovisor/CHANGELOG.md

@@ -0,0 +1,44 @@
+<!--
+Guiding Principles:
+
+Changelogs are for humans, not machines.
+There should be an entry for every single version.
+The same types of changes should be grouped.
+Versions and sections should be linkable.
+The latest version comes first.
+The release date of each version is displayed.
+Mention whether you follow Semantic Versioning.
+
+Usage:
+
+Change log entries are to be added to the Unreleased section under the
+appropriate stanza (see below). Each entry should ideally include a tag and
+the Github issue reference in the following format:
+
+* (<tag>) \#<issue-number> message
+
+The issue numbers will later be link-ified during the release process so you do
+not have to worry about including a link manually, but you can if you wish.
+
+Types of changes (Stanzas):
+
+"Features" for new features.
+"Improvements" for changes in existing functionality.
+"Deprecated" for soon-to-be removed features.
+"Bug Fixes" for any bug fixes.
+"Client Breaking" for breaking Protobuf, gRPC and REST routes used by end-users.
+"CLI Breaking" for breaking CLI commands.
+"API Breaking" for breaking exported APIs used by developers building on SDK.
+"State Machine Breaking" for any changes that result in a different AppState given same genesisState and txList.
+Ref: https://keepachangelog.com/en/1.0.0/
+-->
+
+# Changelog
+
+## v0.1 2021-08-06
+
+This is the first release and we started this changelog on 2021-07-01. See the (README)[https://github.com/cosmos/cosmos-sdk/blob/release/cosmovisor/v0.1.x/cosmovisor/CHANGELOG.md] file for the full list of features.
+
+## Features
+
+* [\#9652](https://github.com/cosmos/cosmos-sdk/pull/9652) Add backup option for cosmovisor.

cosmovisor/README.md

@@ -4,6 +4,10 @@
 
 *Note: If new versions of the application are not set up to run in-place store migrations, migrations will need to be run manually before restarting `cosmovisor` with the new binary. For this reason, we recommend applications adopt in-place store migrations.*
 
+## Contributing
+
+Release branches has the following format `release/cosmovisor/vA.B.x`, where A and B are a number (eg: `release/cosmovisor/v0.1.x`). Releases are tagged using the following format: `cosmovisor/vA.B.C`.
+
 ## Installation
 
 To install `cosmovisor`, run the following command:

cosmovisor/RELEASE_NOTES.md

@@ -0,0 +1,8 @@
+# Cosmovisor v0.1.0 Release Notes
+
+This is the first tracked release of Cosmovisor. It contains the original behavior of scanning app stdin and stdout.
+Since the original design, this release contains one important feature: state backup. Since v0.1, by default, cosmovisor will make a state backup (`<app_directory>/data` directory). Backup will be skipped if `UNSAFE_SKIP_BACKUP=true` is set.
+
+Updates to this release will be pushed to `release/cosmovisor/v0.1.x` branch.
+
+Please see the [CHANGELOG](https://github.com/cosmos/cosmos-sdk/blob/release/cosmovisor/v0.1.x/cosmovisor/CHANGELOG.md) for more details.