new git flow proposal (Chia-Network#1376)

* new git flow proposal

* comma

* added DAG and branching strategy writeup.

* adding newest gitflow diagram

* better formatting on branching section

* better wording and explanations

* input from standup

* changing testnet commentary to reflect feedback

* adams suggestions round 1

CONTRIBUTING.md

@@ -1,5 +1,6 @@
 # Introduction
 
+
 Welcome to the chia-blockchain project!
 We are happy that you are taking a look at the code for Chia, a proof of space and time cryptocurrency.
 
@@ -11,14 +12,38 @@ If you want to learn more about this project, read the [wiki](https://github.com
 
 ## Contributions
 
+Please review this [diagram](https://drive.google.com/file/d/1r7AXTrj7gtD0Xy-9BtTZR6yv7WXMPgeM/view?usp=sharing), to better understand the git workflow.
+
 We would be pleased to accept code contributions to this project.
-As we are in the alpha stage, the main priority is getting a robust blockchain up and running, with as many of the mainnet features as possible.
+As we have now released, the main priority is improving the mainnet blockchain.
 You can visit our [Trello project board](https://trello.com/b/ZuNx7sET) to get a sense of what is in the backlog.
 Generally things to the left are in progress or done. Some things go through "Coming up soon" but some will come directly out of other columns.
 Usually the things closer to the top of each column are the ones that will be worked on soonest.
 If you are interested in cryptography, math, or just like hacking in python, there are many interesting problems to work on.
 Contact any of the team members on [Keybase](https://keybase.io/team/chia_network.public), which we use as the main communication method and you can comment on any Trello card.
 
+We ask that external contributors create a fork of the `main` branch for any feature work they wish to take on.
+
+Members of the Chia organization may create feature branches from the `main` branch.
+
+In the event an emergency fix is required for the release version of Chia, members of the chia organization will create a feature branch from the current release branch `1.0.0`
+
+## Branching Strategy
+
+[Branching Strategy Diagram](https://drive.google.com/file/d/1NF2zdQOfCGlcRu6qKMlV_NlO4uqnIvoE/view?usp=sharing)
+
+1. All changes go into the main branch.
+2. Main is stable at all times, all tests pass.
+3. Features (with tests) are developed and fully tested on feature branches, and reviewed before landing in main.
+4. Chia Network's nodes on the public testnet are running latest version x.y.z
+5. The `main` branch will have a long running `beta testnet` to allow previewing of changes.
+6. Pull Request events may require a `beta testnet` review environment, at the moment this is at the discretion of the reviewer.
+7. Hotfixes land in the release branch they fix, and all later versions. (this will be achieved by regularly merging from 1.0.x -> main).
+8. Hotfixes that are emergency fixes for a specific version will be merged into, and removed from down-stream branches. This allows future merges without issues.
+9. Whoever develops a hotfix is also responsible for merging it into all later branches.
+10. A release branch (e.g. 1.1.x) will be cut prior to a release, in order to separate work that should go into the release from work going into the next major release (main branch). (this pre-release branch will also have a `beta testnet` spun up for preview)
+11. All Merge events will be squashed and merged.
+
 ## Run tests and linting
 
 The first time the tests are run, BlockTools will create and persist many plots. These are used for creating
@@ -57,11 +82,24 @@ workflow.
 3. Install BlackConnect plugin
 4. Set to run python black on save
 5. Set line length to 120
-6. Install mypy plugin
+6. Install these linters https://github.com/Chia-Network/chia-blockchain/tree/main/.github/linters
+
+## Testnets and review environments
+
+With the launch of `1.0.0` we will begin running an official `testnet`.  
+Prior to the release of `1.1.0` there will be two running test nets. `testnet` and `transaction-beta-testnet`. The `transaction-beta-testnet` testnet will be a beta of the pending 1.1 release, which will enable transactions on the chia blockchain.
+Following the release of `1.1.0`, the official `testnet` will include all changes that have been accepted to the current release branch.
+
+Prior to proposing changes to `main`, proposers should consider if running a `beta testnet` review environment will make the reviewer more effective when evaluating a change.
+Changes that impact the block chain could require a review environment before acceptance into `main`. This is at the discretion of the reviewer.
+Chia organization members have been granted CI access to deploy `beta testnets`.
+If you are not a Chia organization member, you can enquire about deploying a `beta testnet` in the public dev keybase channel.
 
 ## Submit changes
 
-To submit changes, please make a pull request to the `dev` development branch.
+To propose changes, please make a pull request to the `main` branch.
+
+To propose changes, for production releases of chia please make a pull request to the latest release branch.
 
 ## Copyright