Rename TemplateWarning -> PowerpointTemplateWarning.

@undergroundquizscene - I think TemplateWarning
is apt to be confusing, since this actually doesn't have
anything to do with what we call 'templates' in pandoc.
Hence the change to a powerpoint-specific name.

src/Text/Pandoc/Logging.hs

@@ -76,7 +76,7 @@ data LogMessage =
   | InlineNotRendered Inline
   | BlockNotRendered Block
   | DocxParserWarning Text
-  | TemplateWarning Text
+  | PowerpointTemplateWarning Text
   | IgnoredIOError Text
   | CouldNotFetchResource Text Text
   | CouldNotDetermineImageSize Text Text
@@ -175,7 +175,7 @@ instance ToJSON LogMessage where
            ["contents" .= toJSON bl]
       DocxParserWarning s ->
            ["contents" .= s]
-      TemplateWarning s ->
+      PowerpointTemplateWarning s ->
            ["contents" .= s]
       IgnoredIOError s ->
            ["contents" .= s]
@@ -294,8 +294,8 @@ showLogMessage msg =
          "Not rendering " <> Text.pack (show bl)
        DocxParserWarning s ->
          "Docx parser warning: " <> s
-       TemplateWarning s ->
-         "Pptx parser warning: " <> s
+       PowerpointTemplateWarning s ->
+         "Powerpoint template warning: " <> s
        IgnoredIOError s ->
          "IO Error (ignored): " <> s
        CouldNotFetchResource fp s ->
@@ -391,7 +391,7 @@ messageVerbosity msg =
        InlineNotRendered{}           -> INFO
        BlockNotRendered{}            -> INFO
        DocxParserWarning{}           -> INFO
-       TemplateWarning{}             -> WARNING
+       PowerpointTemplateWarning{}   -> WARNING
        IgnoredIOError{}              -> WARNING
        CouldNotFetchResource{}       -> WARNING
        CouldNotDetermineImageSize{}  -> WARNING

src/Text/Pandoc/Writers/Powerpoint/Output.hs

@@ -457,7 +457,8 @@ presentationToArchive opts meta pres = do
                                          <> "reference doc or in the default "
                                          <> "reference doc included with pandoc."))
           (Nothing, Just ((element, path, entry) :| _)) -> do
-            P.logOutput (TemplateWarning ("Couldn't find layout named \""
+            P.logOutput (PowerpointTemplateWarning
+                                         ("Couldn't find layout named \""
                                           <> layoutTitle <> "\" in provided "
                                           <> "reference doc. Falling back to "
                                           <> "the default included with pandoc."))