Add read_alitv() to context-specific read_* functions about gggenomes HOT 5 CLOSED

> s <- read_seqs("https://alitvteam.github.io/AliTV/d3/data/chloroplasts.json")
Reading as alitv:
* chloroplasts [https://alitvteam.github.io/AliTV/d3/data/chloroplasts.json]
Error: Internal error in `vec_assign()`: `value` should have been recycled to fit `x`.
Run `rlang::last_error()` to see where the error occurred.

> rlang::last_error()
<error/rlang_error>
Internal error in `vec_assign()`: `value` should have been recycled to fit `x`.
Backtrace:
 1. gggenomes::read_seqs("https://alitvteam.github.io/AliTV/d3/data/chloroplasts.json")
 2. purrr::map2_df(...)
 3. dplyr::bind_rows(res, .id = .id)
 4. vctrs::vec_rbind(!!!dots, .names_to = .id)
Run `rlang::last_trace()` to see the full context.

> f <- read_feats("https://alitvteam.github.io/AliTV/d3/data/chloroplasts.json")
Reading as alitv:
* chloroplasts [https://alitvteam.github.io/AliTV/d3/data/chloroplasts.json]
Error: Internal error in `vec_assign()`: `value` should have been recycled to fit `x`.
Run `rlang::last_error()` to see where the error occurred.

> l <- read_links("https://alitvteam.github.io/AliTV/d3/data/chloroplasts.json")
Reading as alitv:
* chloroplasts [https://alitvteam.github.io/AliTV/d3/data/chloroplasts.json]
Error: Internal error in `vec_assign()`: `value` should have been recycled to fit `x`.
Run `rlang::last_error()` to see where the error occurred.

> gggenomes:::read_alitv_genes("https://alitvteam.github.io/AliTV/d3/data/chloroplasts.json")
# A tibble: 101 x 5
   seq_id  start   end name  class
   <chr>   <int> <int> <chr> <chr>
 1 Cphe_gi 18916 19290 ycf4  ycf  
 2 Cphe_gi 38014 44974 ycf2  ycf  
 3 Cphe_gi 59962 60067 ycf1  ycf  
 4 Cphe_gi 89015 82055 ycf2  ycf  
 5 Evir_gi 22044 28695 ycf2  ycf  
 6 Evir_gi 67783 61132 ycf2  ycf  
 7 Lphi_gi 45475 45351 ycf3  ycf  
 8 Lphi_gi 44641 44411 ycf3  ycf  
 9 Lphi_gi 43675 43522 ycf3  ycf  
10 Lphi_gi 61418 61973 ycf4  ycf  
# … with 91 more rows