slides/yocto-layer-distro: add details

Signed-off-by: Michael Opdenacker <[email protected]>

slides/yocto-layer-distro/yocto-layer-distro.tex

@@ -70,10 +70,11 @@ \subsection{Distro Layers}
 \begin{frame}
   \frametitle{\code{DISTRO_FEATURES}}
   \begin{itemize}
-    \item Lists the features the distribution will provide.
+    \item Lists the features the distribution will enable (SSL, WiFi,
+          Bluetooth\dots).
     \item As for \yoctovar{MACHINE_FEATURES}, this is used by package
       recipes to enable or disable functionalities.
-    \item The \code{bluetooth} feature:
+    \item For example, the \code{bluetooth} feature:
       \begin{itemize}
         \item Asks the \code{bluez} daemon to be built and added to
           the image.
@@ -99,7 +100,9 @@ \subsection{Distro Layers}
     \end{itemize}
     \item The providers' recipes define how to compile or/and install
       the toolchain.
-    \item Toolchains can be built by the build system or external.
+    \item Toolchains can be built by the build system or external
+      (rarely used because toolchains are fast to rebuild thanks
+       to the shared state cache).
   \end{itemize}
 \end{frame}