xonsh: add page (#5709)

pages/common/xonsh.md

@@ -0,0 +1,29 @@
+# xonsh
+
+> Python-powered, cross-platform, Unix-gazing shell.
+> Write and mix sh/Python code in Xonsh (pronounced conch).
+> More information: <https://xon.sh>.
+
+- Start an interactive shell session:
+
+`xonsh`
+
+- Execute a single command and then exit:
+
+`xonsh -c "{{command}}"`
+
+- Run commands from a script file and then exit:
+
+`xonsh {{path/to/script_file.xonsh}}`
+
+- Define environment variables for the shell process:
+
+`xonsh -D{{name1}}={{value1}} -D{{name2}}={{value2}}`
+
+- Load the specified `.xonsh` or `.json` configuration files:
+
+`xonsh --rc {{path/to/file1.xonsh}} {{path/to/file2.json}}`
+
+- Skip loading the `.xonshrc` configuration file:
+
+`xonsh --no-rc`