feat: add support for xonsh (#2807)

* feat: add support for xonsh

* xonsh: add STARSHIP_SESSION_KEY

* xonsh: implement STARSHIP_SESSION_KEY in xonsh

* docs: mention tcsh, elvish, and nu in more places

* xonsh: change STARSHIP_SESSION_KEY implementation

See https://github.com/starship/starship/pull/2807#discussion_r667064149

* xonsh: fix jobs implementation

* xonsh: do not silently discard stderr from starship

1 files changed, 9 insertions, 0 deletions

diff --git a/README.md b/README.md
index 0e78fcfaa..819c2d3e1 100644
--- a/README.md
+++ b/README.md
@@ -251,6 +251,15 @@ shown below. Can't see yours? Have a look at the [extra platform instructions](h
    # ~/.tcshrc
 
    eval `starship init tcsh`
+
+   #### Xonsh
+
+   Add the following to the end of `~/.xonshrc`:
+
+   ```sh
+   # ~/.xonshrc
+
+   execx($(starship init xonsh))
    ```
 
    #### Nushell