Minor readme headline polish

Author: fdwr

README.md

@@ -1,13 +1,13 @@
 # TextLayoutSampler
 Utility to display text drawn via multiple Windows API's simultaneously, to compare differences in rendering, font selection, and glyph shaping.
 
-Supports:
+## Supports:
 - DirectWrite, Direct2D, GDI, GDI+ API's
 - Various attributes: weight, width, slope, family, direction, locale, font size, text color, back color, rotation, pixel zoom...
 - Arbitrary number of text objects with different attributes.
 - Requires Windows 7+. Certain features like Direct2D SVG rendering requires Windows 10 RS4+.
 
-Building:
+## Building:
 - Open TextLayoutSampler.sln in Visual Studio Professional/Community 2019 16.9.3. VS 2017 is too old, as it lacks template constraints.
 - If C++ modules crash the compiler, use normal header files via USE_CPP_MODULES=0 in the project properties preprocessor definitions.