wasm2wat: add page (#2360)

pages/common/wasm2wat.md

@@ -0,0 +1,11 @@
+# wasm2wat
+
+> Convert a file from the WebAssembly binary format to the text format.
+
+- Convert a file to the text format and display it to the console:
+
+`wasm2wat {{file.wasm}}`
+
+- Write the output to a given file:
+
+`wasm2wat {{file.wasm}} -o {{file.wat}}`