CI: caching: upd doc

Author: Anton-Latukha

.github/workflows/caching.yml

@@ -1,8 +1,8 @@
 name: Caching
 
 # Docs on the workflow:
-# 1. GitHub cache scoping goes: main branch -> PR main branch -> PR. (essentially in a tree fashion). That is why it is useful to build caches on `master` - to generate & keep the main project state & they would be shared to the whole tree.
-# 2. GitHub has a 10G default limit of cache pool per repo. HLS is a big project & monorepo of many projects, so to keep cache useful - the main branch state caches should be preserved & their storage preferred to the PRs, since PRs from internal branches - would count into 10G pool, but would be available only inside of the PR scope, which can bork cache fore the whole community. That is short story why `dist-newstyle` (especially full) - is not includded into `master` cache.
+# 1. GitHub cache scoping goes: main branch -> PR main branch -> PR. (essentially in a tree fashion). Building & keeping caches on `master` allows to the main project state cache be shared to the whole tree.
+# 2. GitHub has a 10G as default limit of cache pool per repo. HLS is a big community project & monorepo of many projects, so cache pool can get exhausted & invaidated easilly. Because of that, to keep cache useful - the main branch state caches should be preserved & kept well below the limit & that preferred to the PR caches, since PRs from internal branches - would count into the repo 10G pool, while PR cache is available only inside of the PR, which would bork cache fore the whole community. That is a short story why `dist-newstyle` (especially full) - is not includded into `master` cache.
 
 defaults:
   run: