vignette typos from AFIDEP work

[jeffeaton]

Some typos and out-of-date elements in example vignette from review with AFIDEP (thanks @mcewenkhundi):

• second appearance of artnum_quarter_id_t1 should be _t2
  

  naomi/vignettes_src/model-workflow.R

  Line 93 in 2a45128

  #' * `artnum_quarter_id_t1` and `artnum_quarter_id_t1` are the time point at

• Referring to ANC quarter IDs is out of date. These are now provided as full year data.
  

  naomi/vignettes_src/model-workflow.R

  Lines 97 to 99 in 2a45128

  	#' * `anc_quarter_id_t1` and `anc_quarter_id_t2` are typically a range of 3-4 quarters. Data will be aggregated over these quarters for a larger sample size. They
  	#' will typically be consecutive quarters, though a quarter could be dropped for
  	#' example if there were reporting problems known to affect a given quarter.

• Plot does not select the calendar_quarter, so it is probably overplotting all quarters
  

  naomi/vignettes_src/model-workflow.R

  Lines 247 to 258 in 2a45128

  	#' 15-49 prevalence by district
  	##+ prev_by_district_15, fig.height = 4, fig.width = 7
  	indicators %>%
  	filter(age_group == "Y015_049",
  	indicator == "prevalence",
  	area_level == 4) %>%
  	ggplot(aes(fill = mode)) +
  	geom_sf() +
  	viridis::scale_fill_viridis(labels = scales::percent_format()) +
  	th_map() +
  	facet_wrap(~sex)