docs: moved contributing to docs, refined upgrading and concepts docu…

…mentation

README.md

@@ -208,7 +208,7 @@ Read the dedicated [testing documentation](./docs/TESTING.md) to learn more abou
 
 ## Contributing
 
-Read the [Contributing Guide](./CONTRIBUTING.md) for details on how you can get involved. In case you find an issue with the examples or the SDK itself, feel free to submit
+Read the [Contributing Guide](docs/CONTRIBUTING.md) for details on how you can get involved. In case you find an issue with the examples or the SDK itself, feel free to submit
 an [issue report](https://github.com/golemfactory/golem-js/issues) to the repository.
 
 ## Discord

docs/CONCEPTS.md

@@ -102,17 +102,6 @@ When using the `ResourceRental` model, you can still access these lower level do
 
 When you obtain resources via the Golem Network, your _Golem Virtual Machine Image (GVMI for short)_ is going to be deployed by `golem-js` into the _Activity_ running on the Provider. Technically, on the Provider instantiates an _ExeUnit_ which is a physical implementation of the _Activity_ of the Golem Network Protocol. Without digging in too much details, it's this _ExeUnit_ which at the end performs the operations that you issue via the Golem Network.
 
-If you're familiar with Docker, you can picture the architecture in the following way:
-
-| Golem              | Docker       | Kubernetes   |
-| ------------------ | ------------ | ------------ |
-| GVMI               | Docker Image | Docker Image |
-| Activity (ExeUnit) | Container    | Container    |
-
-> **DISCLAIMER**
->
-> The above comparison is used only for illustrative purposes. Golem GVMIs, ExeUnits and Activities behave differently compared to Docker or Kubernetes.
-
 As a Requestor you're interested in quickly executing your commands within the container that runs your image. The `ExeUnit` abstraction delivered by the SDK is meant to do enable you to do so. The `ExeUnit` type documents the available features of particular ExeUnit type so that you can build up your solution faster, and in a type-safe manner.
 
 ### What it should do

CONTRIBUTING.md → docs/CONTRIBUTING.md

@@ -7,7 +7,7 @@ You want to contribute to `golem-js`? That's great! This guide will help you get
 1. Clone this repository
 2. In the root of this project run `npm install` to install all necessary dependencies
 3. To build the SDK run `npm run build`
-4. Install yagna as described in the [README](./README.md) file - you will need it to test your changes against testnet (no real funds will be required to execute workloads on Golem Network)
+4. Install yagna as described in the [README](../README.md) file - you will need it to test your changes against testnet (no real funds will be required to execute workloads on Golem Network)
 
 ### Unit Testing
 

docs/UPGRADING.md

@@ -1,6 +1,6 @@
 # Upgrade Guide
 
-This document describes the breaking changes introduced in each major version of MyLibraryJS and the necessary steps you need to take to ensure your application continues to work correctly.
+This document describes the breaking changes introduced in each major version of `golem-js` and the necessary steps you need to take to ensure your application continues to work correctly.
 
 ## Upgrading from 2.x to 3.x
 
@@ -84,6 +84,18 @@ Areas where the changes are needed:
 
 - Instead of referring the `TaskExecutor` instance in the `map` function, you need to switch to the `ExeUnit` instance provided by the `ResourceRental`
 
+> **IMPORTANT DIFFERENCE**
+>
+> `TaskExecutor` by default assumed that users want to run these commands in parallel, so it
+> was establishing up to 5 agreements with different providers and then sent out these
+> commands to different providers to leverage parallelism.
+>
+> With `[email protected]`, when you use `oneOf` to rent resources, you are establishing one agreement
+> with a single provider and the commands which you issue with `Array.map` will be executed
+> sequentially by that single provider.
+>
+> If you want to achieve _parallel command execution_ on different providers, refer to the [Engaging with many providers at the same time](#engaging-with-many-providers-at-the-same-time) example.
+
 **Before:**
 
 ```ts