emulate: add page (#22278)

Co-authored-by: Dylan <145150333+dmmqz@users.noreply.github.com>
Co-authored-by: Ivan Baluta <ivanbaluta.dev@gmail.com>

pages/common/emulate.md

@@ -0,0 +1,25 @@
+# emulate
+
+> Reset shell options to match a certain shell's behavior.
+> Also used to ensure a shell function runs with the default configuration.
+> More information: <https://github.com/antonio/zsh-config/blob/master/help/emulate>.
+
+- Print current emulation mode:
+
+`emulate`
+
+- Adjust settings of the current shell session to mimic Bash:
+
+`emulate bash`
+
+- Evaluate a [c]ommand within temporary emulation:
+
+`emulate ksh -c "{{echo hi}}"`
+
+- Emulate the default Zsh, [R]esetting options when possible:
+
+`emulate zsh -R`
+
+- Scope emulation to the current function:
+
+`{{my_function}}() { emulate -L {{zsh|sh|ksh|csh}}; {{ls}} }`