Update dependencies.md (#12598)

Fix broken grammar and hl_lines.

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## Summary

Some simple doc fixes.

<!-- What's the purpose of the change? What does it do, and why? -->

## Test Plan

N/A

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---------

Co-authored-by: Zanie Blue <contact@zanie.dev>

docs/concepts/projects/dependencies.md

@@ -198,9 +198,9 @@ dependencies = [
 The `tool.uv.sources` table extends the standard dependency tables with alternative dependency
 sources, which are used during development.
 
-Dependency sources add support common patterns that are not supported by the `project.dependencies`
-standard, like editable installations and relative paths. For example, to install `foo` from a
-directory relative to the project root:
+Dependency sources add support for common patterns that are not supported by the
+`project.dependencies` standard, like editable installations and relative paths. For example, to
+install `foo` from a directory relative to the project root:
 
 ```toml title="pyproject.toml" hl_lines="7"
 [project]
@@ -484,7 +484,7 @@ environment markers.
 
 For example, to pull in different `httpx` tags on macOS vs. Linux:
 
-```toml title="pyproject.toml" hl_lines="8-9 13-14"
+```toml title="pyproject.toml" hl_lines="6-7"
 [project]
 dependencies = ["httpx"]