psalm: add page (#5237)

pages/common/psalm.md

@@ -0,0 +1,32 @@
+# psalm
+
+> A static analysis tool for finding errors in PHP applications.
+> More information: <https://psalm.dev>.
+
+- Generate a Psalm configuration:
+
+`psalm --init`
+
+- Analyse the current working directory:
+
+`psalm`
+
+- Analyse a specific directory or file:
+
+`psalm {{path/to/file_or_directory}}`
+
+- Analyse a project with a specific configuration file:
+
+`psalm --config {{path/to/psalm.xml}}`
+
+- Include informational findings in the output:
+
+`psalm --show-info`
+
+- Analyse a project and display statistics:
+
+`psalm --stats`
+
+- Analyse a project in parallel with 4 threads:
+
+`psalm --threads {{4}}`