Completed on-line documentation.

src/site/markdown/design/digital-elevation-model.md

src/site/markdown/design/overview.md

src/site/markdown/design/preliminary-design.md

src/site/markdown/design/technical-choices.md

src/site/resources/images/aberration-of-light-correction.png

src/site/resources/images/flat-body-interpolation-error.png

src/site/resources/images/light-time-correction.png

src/site/resources/images/precession-nutation-error.png

src/site/site.xml