docs: Add running context

Signed-off-by: nullday <aseaday@hotmail.com>

docs/proposals/20220826-image-runtime-redistributed-metadata.md

@@ -10,12 +10,14 @@ The `envd` would add (runing graph metadata)[https://github.com/tensorchord/envd
 
 This proposal is part of effort to define what the artifact `envd` delivery and decoupling the phases of build and runing. It will be friendly for running a envd environment even at the absence of `build.env`.
 
+the concept of `running context` is a also needed as addition of `build contxt` for example:
 
+- An engineer build a easy-to-use env for his/her interns for the quick use of company tools.
+- Kubernetes remote runtime support in the future.
 
 ## Goals
 - Provide internal API:
     - read runtime metadata
     - write runtime metadata
-- `up` and `run` command doesn't need to interpret the `build.env`
-
+- `up` and `run` command doesn't need to interpret the `build.env`. `run` command can run a built env image with attachment of current working directory as `running context`.