Fix order of posts, add some front matter

rosalind/07-iprb.md

@@ -1,3 +1,10 @@
++++
+using Dates
+date = Date("2026-02-18")
+title = "Problem 7: Mendel's First Law"
+rss_descr = "Solving Rosalind problem IPRB — computing the probability of dominant-allele offspring — using base Julia."
++++
+
 # Mendel's First Law
 
 🤔 [Problem link](https://rosalind.info/problems/iprb/)

rosalind/08-prot.md

@@ -1,3 +1,10 @@
++++
+using Dates
+date = Date("2026-02-20")
+title = "Problem 8: Translating RNA into Protein"
+rss_descr = "Solving Rosalind problem PROT using base Julia."
++++
+
 # Translating RNA into Protein
 
 🤔 [Problem link](https://rosalind.info/problems/prot/)
@@ -204,4 +211,4 @@ Similar to our function, the BioSequences function also throws an error if the i
 
 ```julia
 translate(rna"AUGGA")
-```
+```

rosalind/09-subs.md

@@ -1,3 +1,10 @@
++++
+using Dates
+date = Date("2026-02-23")
+title = "Problem 9: Finding a Motif in DNA"
+rss_descr = "Solving Rosalind problem SUBS — finding all locations of a motif in a DNA string — using base Julia."
++++
+
 # Finding a Motif in DNA
 
 🤔 [Problem link](https://rosalind.info/problems/subs/)

utils.jl

@@ -53,7 +53,12 @@ end
 
 function hfun_list_dir(args::Vector{String})
     isempty(args) && return ""
-    return _render_posts(get_posts("", args[1]))
+    posts = get_posts("", args[1])
+    sort!(posts, by=p -> begin
+        m = match(r"/(\d+)[^/]*$", p.href)
+        m === nothing ? typemax(Int) : parse(Int, m.captures[1])
+    end)
+    return _render_posts(posts)
 end
 
 function hfun_list_series()