The first document of Vatican II was the Constitution on the Liturgy, Sacrosanctum Concilium, which is at
vatican.va/archive/hist_councils/ii_vatican_council/documents/vat-ii_const_19631204_sacrosanctum-concilium_en.html . It said:
“25. The liturgical books are to be revised as soon as possible; experts are to be employed on the task, and bishops are to be consulted, from various parts of the world.”
One of these liturgical books was the Roman Missal. The revised General Instruction of the Roman Missal of 1970 said: “262. In every church there should ordinarily be a fixed, dedicated altar, which should be freestanding to allows the ministers to walk around it easily and Mass to be celebrated facing the people.”
From the 2002 General Instruction of the Roman Missal (GIRM) approved for the USA, which can be accessed from
romanrite.com/girm.html :
“299. The altar should be built apart from the wall, in such a way that it is possible to walk around it easily and that Mass can be celebrated at it facing the people, which is desirable wherever possible.”
The term “facing” appears 16 times in this 2002 GIRM, in 105, 124, 138, 146, 154, 157, 165, 185, 243, 244, 257, 268 (twice), 286, 299, and 310. The phrase “facing the people” occurs 10 times, and “facing the faithful” once.