Merge pull request #2388 from EspressoSystems/jr/doc_text_editor

[DOCS] - Document text editor usage

README.md

@@ -195,27 +195,12 @@ For espresso developers we have written up a description of our workflow [here](
 
 # Extra Editor Configuration
 
-## Neovim
+Choose an async runtime to use before launching a text editor. This may be done by setting the environment RUSTFLAGS. For example:
 
-Copy `.nvim/example.env.lua` to `.nvim/env.lua`. The purpose of this file is to return to neovim the requisite feature flags.
-
-Then load this file when configuring `rust-tools`:
-
-```lua
-rust_tools.setup(
-  {server =
-    {settings =
-      {
-        ["rust-analyzer"] =
-          {cargo =
-            {features =
-              loadfile(".nvim/env.lua") and { loadfile(".nvim/env.lua")() } or "all"
-            }
-          }
-      }
-    }
-  }
-)
+```
+export RUSTFLAGS='--cfg async_executor_impl="tokio" --cfg async_channel_impl="tokio"' # export RUSTFLAGS so the editor is aware of extra flags
+nvim # launch text editor of choice. We choose neovim in this example
+unset RUSTFLAGS # Unset rustflags so we may continue to use the justfile. The justfile sets these particular config options
 ```
 
 # Debugging