Merge pull request #408 from Murdalay/v1

edited english version of BEMHTML reference + links was fixed
Add release notes for 1.2.0
Merge pull request #388 from bem/issues/377@v1

Release notes for bem-core@1.2.0
1.2.0
i-bem: Use boolean modifiers for `i-bem_elem-instances_yes` and `i-bem__dom_elem-instances_yes`
Merge pull request #430 from aristov/issues/352@v1

i-bem: Use boolean modifiers for `i-bem_elem-instances_yes` and `i-bem__dom_elem-instances_yes`
Минимальные правки текста

Пропущенные знаки препинания, буквы, отступы
Merge pull request #452 from Murdalay/v1

i-bem-js.md baseMix description was added