documentation: fix typos
What it does:
The following pull-request fixes typos found in the documentation which was noticed when attempting to add an
adopter listing following the documentation from: https://ecdtools.eclipse.org/adopters/how-to-be-listed-as-an-adopter/.
The typo referenced in the documentation is
static/assets/images/adoptors which should be
static/assets/images/adopters based on the path:
Signed-off-by: vince-fugnitto firstname.lastname@example.org