perf: apply (micro) optimization on SerializedHyphenationPatterns (#689)

This PR applies a micro optimization on `SerializedHyphenationPatterns`,
which allow reading `rootOffset` directly without having to parse then
cache it.

It should not affect storage space since no new bytes are added.

This also gets rid of the linear cache search whenever
`liangBreakIndexes` is called. In theory, the performance should be
improved a bit, although it may be too small to be noticeable in
practice.

master branch:

```
english: 99.1023%
french: 100%
german: 97.7289%
russian: 97.2167%
spanish: 99.0236%
```

This PR:

```
english: 99.1023%
french: 100%
german: 97.7289%
russian: 97.2167%
spanish: 99.0236%
```

---

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code? PARTIALLY - mostly IDE
tab-autocompletions

docs/hyphenation-trie-format.md

@@ -45,22 +45,9 @@ byte arrays, and emits headers under
 `SerializedHyphenationPatterns` descriptor so the reader can keep the automaton
 in flash.
 
-To refresh the firmware assets after updating the `.bin` files, run:
+A convenient script `update_hyphenation.sh` is used to update all languages.
+To use it, run:
 
-```
-./scripts/generate_hyphenation_trie.py \
-    --input lib/Epub/Epub/hyphenation/tries/en.bin \
-    --output lib/Epub/Epub/hyphenation/generated/hyph-en.trie.h
-
-./scripts/generate_hyphenation_trie.py \
-    --input lib/Epub/Epub/hyphenation/tries/fr.bin \
-    --output lib/Epub/Epub/hyphenation/generated/hyph-fr.trie.h
-
-./scripts/generate_hyphenation_trie.py \
-    --input lib/Epub/Epub/hyphenation/tries/de.bin \
-    --output lib/Epub/Epub/hyphenation/generated/hyph-de.trie.h
-
-./scripts/generate_hyphenation_trie.py \
-    --input lib/Epub/Epub/hyphenation/tries/ru.bin \
-    --output lib/Epub/Epub/hyphenation/generated/hyph-ru.trie.h
+```sh
+./scripts/update_hypenation.sh
 ```