Fix: Fix media paths not being replaced with relative paths

This bug affects all prior versions. Because media paths were not normalized to only use front slashes, and attachment (a type of media) used a capitalized drive letter, the subsequent replacement of absolute media paths with relative media paths fails. The user sees media with absolute paths in the final markdown, and the media is not rendered by markdown previewers because the `file://` uri scheme is not present in the URI.

The key is to normalize all media paths in the final markdown to use front slashes and with a lowercase drive letter, so that the search and replacement of absolute paths with relative paths in media paths works. Now the final markdown correctly contains relative media paths, and media is recognized in markdown previewers.

ConvertOneNote2MarkDown-v2.ps1

@@ -121,13 +121,13 @@ Function ProcessSections ($group, $FilePath) {
 
             # set media location (central media folder at notebook-level or adjacent to .md file) based on initial user prompt
             if ($medialocation -eq 2) {
-                $mediaPath = $fullexportdirpath
+                $mediaPath = $fullexportdirpath.Replace('\', '/') # Normalize markdown media paths to use front slashes, i.e. '/'
                 $levelsprefix = ""
             }
             else {
-                $mediaPath = $NotebookFilePath
+                $mediaPath = $NotebookFilePath.Replace('\', '/') # Normalize markdown media paths to use front slashes, i.e. '/'
             }
-            $mediaPath2 = $mediaPath.Substring(0, 1).toupper() + $mediaPath.Substring(1)
+            $mediaPath = ($mediaPath.Substring(0, 1).tolower() + $mediaPath.Substring(1)).Replace('\', '/') # Normalize markdown media paths to use front slashes, i.e. '/'
 
             # in case multiple pages with the same name exist in a section, postfix the filename. Run after pages
             if ([System.IO.File]::Exists("$($fullfilepathwithoutextension).md")) {
@@ -202,7 +202,7 @@ Function ProcessSections ($group, $FilePath) {
                 # Change MD file Object Name References
                 try {
                     $pageinsertedfile2 = $pageinsertedfile.InsertedFile.preferredName.Replace("$", "\$").Replace("^", "\^").Replace("'", "\'")
-                    ((Get-Content -path "$($fullfilepathwithoutextension).md" -Raw).Replace("$($pageinsertedfile2)", "[$($destfilename)]($($mediaPath2)\media\$($destfilename))")) | Set-Content -Path "$($fullfilepathwithoutextension).md"
+                    ((Get-Content -path "$($fullfilepathwithoutextension).md" -Raw).Replace("$($pageinsertedfile2)", "[$($destfilename)]($($mediaPath2)/media/$($destfilename))")) | Set-Content -Path "$($fullfilepathwithoutextension).md"
 
                 }
                 catch {
@@ -268,9 +268,9 @@ Function ProcessSections ($group, $FilePath) {
             # change MD file Image Path References
             try {
                 # Change MD file Image Path References in Markdown
-                ((Get-Content -path "$($fullfilepathwithoutextension).md" -Raw).Replace("$($mediaPath2)\media\", "$($levelsprefix)/media/")) | Set-Content -Path "$($fullfilepathwithoutextension).md"
+                ((Get-Content -path "$($fullfilepathwithoutextension).md" -Raw).Replace("$($mediaPath)/media/", "$($levelsprefix)/media/")) | Set-Content -Path "$($fullfilepathwithoutextension).md"
                 # Change MD file Image Path References in HTML
-                ((Get-Content -path "$($fullfilepathwithoutextension).md" -Raw).Replace("$($mediaPath2)", "$($levelsprefix)")) | Set-Content -Path "$($fullfilepathwithoutextension).md"
+                ((Get-Content -path "$($fullfilepathwithoutextension).md" -Raw).Replace("$($mediaPath)", "$($levelsprefix)")) | Set-Content -Path "$($fullfilepathwithoutextension).md"
             }
             catch {
                 Write-Host "Error while renaming image file path references for file '$($page.name)': $($Error[0].ToString())" -ForegroundColor Red