Use "color vision deficiency" instead of "colorblindness"

[patrickhlauke]

• includes reformatting/removal of empty lines on some of the files

follow-up to #1033 where I took the opportunity to address F81

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[mbgower]

@bruce-usab if you have time, can you please put a diff version of these rendered files in the main issue comment? It will make it easier for people to identify the changes.

[patrickhlauke]

content changes:

techniques/failures/F13.html
Line 23 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-b3d4f8f764488787e908396902c1fc2310de0c1d64521eb2120a603d5fde8f4dR23

techniques/general/G183.html
Line 27 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-7e7f4bd75b7e1985648327af54e0f6a4fd4b48452425a2579836633dd8c5a4dcR27

understanding/20/contrast-minimum.html
Line 28 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-f36712c2f81b39397d15f61ca60019fc91e91e6a0e080257a7ca481d667564e3R28
Line 279 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-f36712c2f81b39397d15f61ca60019fc91e91e6a0e080257a7ca481d667564e3R279

understanding/20/error-identification.html
Line 87 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-7ab9dda99450b42951e62a63fb7f6fff1783fcb67381d09992ff71ad5275d1d4R87

understanding/20/use-of-color.html
Line 119 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-6c2c8b7bdda688b21fd37256a832788d6309f1f448062533f5ce4535595ea549R119
Line 157 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-6c2c8b7bdda688b21fd37256a832788d6309f1f448062533f5ce4535595ea549R157
Line 163 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-6c2c8b7bdda688b21fd37256a832788d6309f1f448062533f5ce4535595ea549R163

working-examples/link-contrast/index.html
Line 77 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-9b43d7748a04c5d57f2501fca7752650b7e5dbd96e5186f9f115717b1538d793R77
Line 87 https://github.com/w3c/wcag/pull/4472/files?diff=split&w=1#diff-9b43d7748a04c5d57f2501fca7752650b7e5dbd96e5186f9f115717b1538d793R87