Quote install commands so they work in zsh; MarkItdown->MarkItDown

In zsh (default macOS shell since 2019, default on many Linux distros),
`[` and `]` are pathname-expansion metacharacters, so `pip install
markitdown[all]` fails with:

    zsh: no matches found: markitdown[all]

The top-level README.md already uses the quoted form
(`pip install 'markitdown[all]'`) throughout. This commit brings the
package README and two user-facing dependency-missing error messages
into alignment with that convention, so users copy-pasting from PyPI
or from a raised MissingDependencyException get a command that works
in every mainstream shell.

- packages/markitdown/README.md: quote the PyPI install and the
  editable-install-from-source example.
- _exceptions.py: quote the three `pip install` examples inside
  MISSING_DEPENDENCY_MESSAGE (shown to end users when an optional
  converter dep is missing).
- _transcribe_audio.py: quote the two `pip install` examples in
  the raised MissingDependencyException text, and fix a lowercase
  'MarkItdown' -> 'MarkItDown' product-name typo in the same string.

Bash/sh/dash treat quoted and unquoted forms identically, so this is
a strict improvement.

Independently proposed by community PRs #1172, #1577, #1602, and #2062
(all still open); fixes referenced issue #1574. Consolidating here to
resolve them in one place alongside the wider prose cleanup.

packages/markitdown/README.md

@@ -13,7 +13,7 @@
 From PyPI:
 
 ```bash
-pip install markitdown[all]
+pip install 'markitdown[all]'
 ```
 
 From source:
@@ -21,7 +21,7 @@ From source:
 ```bash
 git clone git@github.com:microsoft/markitdown.git
 cd markitdown
-pip install -e packages/markitdown[all]
+pip install -e 'packages/markitdown[all]'
 ```
 
 ## Usage

packages/markitdown/src/markitdown/_exceptions.py

@@ -2,9 +2,9 @@ from typing import Optional, List, Any
 
 MISSING_DEPENDENCY_MESSAGE = """{converter} recognized the input as a potential {extension} file, but the dependencies needed to read {extension} files have not been installed. To resolve this error, include the optional dependency [{feature}] or [all] when installing MarkItDown. For example:
 
-* pip install markitdown[{feature}]
-* pip install markitdown[all]
-* pip install markitdown[{feature}, ...]
+* pip install 'markitdown[{feature}]'
+* pip install 'markitdown[all]'
+* pip install 'markitdown[{feature}, ...]'
 * etc."""
 
 

packages/markitdown/src/markitdown/converters/_transcribe_audio.py

@@ -24,7 +24,10 @@ def transcribe_audio(file_stream: BinaryIO, *, audio_format: str = "wav") -> str
     # Check for installed dependencies
     if _dependency_exc_info is not None:
         raise MissingDependencyException(
-            "Speech transcription requires installing MarkItdown with the [audio-transcription] optional dependencies. E.g., `pip install markitdown[audio-transcription]` or `pip install markitdown[all]`"
+            "Speech transcription requires installing MarkItDown with the "
+            "[audio-transcription] optional dependencies. E.g., "
+            "`pip install 'markitdown[audio-transcription]'` or "
+            "`pip install 'markitdown[all]'`"
         ) from _dependency_exc_info[
             1
         ].with_traceback(  # type: ignore[union-attr]