Fix image and formatting in README (#973)

Signed-off-by: Cary Phillips <cary@ilm.com>

README.md

@@ -6,7 +6,7 @@
 
 # OpenEXR
 
-<img align="right" src="/OpenEXR/doc/images/windowExample1.png">
+<img align="right" src="docs/images/windowExample1.png">
 
 OpenEXR provides the specification and reference implementation of the
 EXR file format, the professional-grade image storage format of the
@@ -63,12 +63,11 @@ Platform](https://vfxplatform.com).
 
 With the release of OpenEXR 3, the Imath library formerly distributed
 via the IlmBase component of OpenEXR is now an independent library
-dependency, available for download from
-https:://github.com/AcademySoftwareFoundation/Imath.  You can choose
-to build OpenEXR against an external installation of Imath, or the
-default CMake configuration will download and build it automatically
-during the OpenEXR build process.  Note that the half 16-bit floating
-point data type is included in Imath.
+dependency, available for download from https:://github.com/AcademySoftwareFoundation/Imath.
+You can choose to build OpenEXR against an external installation of
+Imath, or the default CMake configuration will download and build it
+automatically during the OpenEXR build process.  Note that the half
+16-bit floating point data type is included in Imath.
 
 See the [porting
 guide](https://github.com/AcademySoftwareFoundation/Imath/blob/master/docs/PortingGuide2-3.md)