psysh: add page

pages/common/psysh.md

@@ -0,0 +1,16 @@
+# psysh
+
+> A runtime developer console, interactive debugger and REPL for PHP.
+> More information: <https://psysh.org>.
+
+- Open a shell in the current directory:
+
+`psysh`
+
+- Open a shell in a specific directory:
+
+`psysh --cwd {{path/to/directory}}`
+
+- Use a specific configuration file:
+
+`psysh --config {{path/to/file}}`