Fix og:image path to be absolute

This change resolves the relative note image path to make
an absolute url.

For `blog/post.md` with a `![img](media/image.png)`, the og:image is:
- Before: `siteUrl/media/image.png`
- After:  `siteUrl/blog/media/image.png`

Author: TristanCacqueray

emanote/src/Emanote/Model/Note.hs

@@ -30,7 +30,7 @@ import Network.URI.Slug (Slug)
 import Optics.Core ((%), (.~))
 import Optics.TH (makeLenses)
 import Relude
-import System.FilePath (takeFileName, (</>))
+import System.FilePath (takeDirectory, takeFileName, (</>))
 import Text.Pandoc (readerExtensions, runPure)
 import Text.Pandoc.Builder qualified as B
 import Text.Pandoc.Definition (Pandoc (..))
@@ -368,9 +368,8 @@ parseNoteMarkdown scriptingEngine pluginBaseDir fp md = do
             tell [toText $ "Pandoc filter " <> p <> " not found in any of: " <> show pluginBaseDir]
             pure Nothing
           (x : _) -> pure $ Just x
-
       doc <- applyPandocFilters scriptingEngine filterPaths $ preparePandoc doc'
-      let meta = applyNoteMetaFilters doc frontmatter
+      let meta = applyNoteMetaFilters (takeDirectory fp) doc frontmatter
       pure (doc, meta)
   where
     withAesonDefault default_ mv =
@@ -381,8 +380,8 @@ defaultFrontMatter :: Aeson.Value
 defaultFrontMatter =
   Aeson.toJSON $ Map.fromList @Text @[Text] $ one ("tags", [])
 
-applyNoteMetaFilters :: Pandoc -> Aeson.Value -> Aeson.Value
-applyNoteMetaFilters doc =
+applyNoteMetaFilters :: FilePath -> Pandoc -> Aeson.Value -> Aeson.Value
+applyNoteMetaFilters fileDirectory doc =
   addTagsFromBody
     >>> addDescriptionFromBody
     >>> addImageFromBody
@@ -407,7 +406,7 @@ applyNoteMetaFilters doc =
     -- `![[foo.jpeg]]` is not handled at all.
     addImageFromBody =
       overrideAesonText ("page" :| ["image"]) $ \case
-        B.Image _ _ (url, _) -> [url]
+        B.Image _ _ (url, _) -> [T.pack (fileDirectory </> T.unpack url)]
         _ -> mempty
     overrideAesonText :: forall a. (W.Walkable a Pandoc) => NonEmpty Text -> (a -> [Text]) -> Aeson.Value -> Aeson.Value
     overrideAesonText key f frontmatter =