Storing Doc Topic Distribution with LDA model

This is mostly annoyance. I think it would be logical if the lda_model would also store the resulting doc_topic_distr as part of the public fields.

`doc_topic_distr =
lda_model$fit_transform(x = dtm, n_iter = 1000,
convergence_tol = 0.001, n_check_convergence = 25,
progressbar = FALSE)`

We can see that topic_word_distribution is already there so having doc_topic_distribution would make sense as well. Or have I misunderstood something.

`` > lda_model

Inherits from:
Public:
clone: function (deep = FALSE)
components: active binding
fit_transform: function (x, n_iter = 1000, convergence_tol = 0.001, n_check_convergence = 10,
get_top_words: function (n = 10, topic_number = 1L:private$n_topics, lambda = 1)
initialize: function (n_topics = 10L, doc_topic_prior = 50/n_topics, topic_word_prior = 1/n_topics)
plot: function (lambda.step = 0.1, reorder.topics = FALSE, doc_len = private$doc_len,
topic_word_distribution: active binding
transform: function (x, n_iter = 1000, convergence_tol = 0.001, n_check_convergence = 5, ``