fix #33 minimal Buffer with docs, in a separate package

lynglib/src/jvmTest/kotlin/BookTest.kt

@@ -265,6 +265,11 @@ class BookTest {
         runDocTests("../docs/Map.md")
     }
 
+    @Test
+    fun testBuffer() = runTest {
+        runDocTests("../docs/Buffer.md")
+    }
+
     @Test
     fun testSampleBooks() = runTest {
         for (bt in Files.list(Paths.get("../docs/samples")).toList()) {