;ci: add consistent greppable summaries for all workflows

.github/workflows/README

@@ -1,5 +1,7 @@
 hledger github actions workflows.
 
+These have a greppable one-line "ACTION:" comment near the top summarising their current intended behaviour.
+These should be kept up to date.
 
 docs:
 

.github/workflows/binaries-linux-arm32v7.yml

@@ -1,9 +1,6 @@
 # This was used for certain raspberry pi hardware and perhaps needs update.
 # Runs on any push to binaries-linux-arm32v7.
-# Produces optimised static arm32v7 linux  binaries,
-# using GHC 8.10.4 and cabal.
-# Currently runs no tests.
-# Slow, will probably time out.
+# ACTION: Builds and saves linux arm32v7 static binaries, using docker-arm32v7/Dockerfile and cabal and the ghc specified there. Slow, may time out.
 
 name: binaries-linux-arm32v7
 on:

.github/workflows/binaries-linux-x64-stack.yml

@@ -1,5 +1,6 @@
 # Runs on any push to binaries-linux-x64-stack.
-# Like binaries-linux-x64.yml except it builds with stack instead of cabal.
+# ACTION: Builds and saves mac x64 static binaries with stack and the default ghc. May not work,
+# the cabal-based binaries-linux-x64.yml is normally used instead.
 
 name: binaries-linux-x64-stack
 on:

.github/workflows/binaries-linux-x64.yml

@@ -1,6 +1,5 @@
 # Runs on any push to binaries-linux-x64 or binaries.
-# Produces optimised static x64 linux  binaries,
-# using the GHC version below and cabal and Alpine linux, 
+# ACTION: Builds and saves linux x64 static binaries with cabal and the ghc version below and Alpine linux,
 # which provides the statically-linkable musl.
 
 name: binaries-linux-x64

.github/workflows/binaries-mac-arm64.yml

@@ -1,6 +1,5 @@
 # Runs on any push to binaries-mac-arm64 or binaries.
-# Produces optimised mac arm64 binaries and runs unit/doc/functional tests,
-# using the default stack.yaml's GHC version.
+# ACTION: Builds, tests and saves mac arm64 dynamic binaries with stack and the default ghc.
 
 name: binaries-mac-arm64
 on:

.github/workflows/binaries-mac-x64.yml

@@ -1,6 +1,5 @@
 # Runs on any push to binaries-mac-x64 or binaries.
-# Produces optimised mac x64 binaries and runs unit/doc/functional tests,
-# using the default stack.yaml's GHC version.
+# ACTION: Builds, tests and saves mac x64 dynamic binaries with stack and the default ghc.
 
 name: binaries-mac-x64
 on:

.github/workflows/binaries-windows-x64.yml

@@ -1,7 +1,5 @@
 # Runs on any push to binaries-windows-x64 or binaries.
-# Produces optimised windows binaries,
-# using the default stack.yaml's GHC version.
-# Currently runs no tests.
+# ACTION: Builds and saves windows x64 binaries with stack and the default ghc.
 
 name: binaries-windows-x64
 on:

.github/workflows/ci.yml

@@ -1,8 +1,7 @@
 # The main hledger continuous integration tests.
-# Builds all packages expecting no warnings, runs lots of tests,
-# and on success, saves the binaries as an artifact.
-# Code must pass this successfully before it can be merged or pushed to master
-# (https://github.com/simonmichael/hledger/settings/branch_protection_rules/17386787).
+# ACTION: Builds, tests and saves linux x64 dynamic binaries with stack and the default ghc.
+# Code must pass this successfully before it can be merged or pushed to master.
+# https://github.com/simonmichael/hledger/settings/branch_protection_rules/17386787
 
 name: ci
 

.github/workflows/oldest.yml

@@ -1,4 +1,4 @@
-# Test that hledger still builds with the oldest supported GHC version.
+# ACTION: Builds and tests with stack and the oldest supported GHC version.
 
 name: oldest
 

.github/workflows/release.yml

@@ -1,4 +1,4 @@
-# Create/update a draft release when a release tag is pushed.
+# ACTION: Creates/updates a draft release when a release tag is pushed.
 # Expects that the main binaries* workflows have been completed first.
 # XXX Triggers too much, eg on pushing VER.99 dev tags; those releases must be deleted manually.