fix(inputs/zfs): resolve README.md linter issues (#10109)

plugins/inputs/zfs/README.md

@@ -4,7 +4,7 @@ This ZFS plugin provides metrics from your ZFS filesystems. It supports ZFS on
 Linux and FreeBSD. It gets ZFS stat from `/proc/spl/kstat/zfs` on Linux and
 from `sysctl`, 'zfs' and `zpool` on FreeBSD.
 
-### Configuration:
+## Configuration
 
 ```toml
 [[inputs.zfs]]
@@ -27,7 +27,7 @@ from `sysctl`, 'zfs' and `zpool` on FreeBSD.
   # datasetMetrics = false
 ```
 
-### Measurements & Fields:
+### Measurements & Fields
 
 By default this plugin collects metrics about ZFS internals pool and dataset.
 These metrics are either counters or measure sizes
@@ -220,7 +220,7 @@ On FreeBSD:
   - usedsnap (integer, bytes
   - usedds (integer, bytes)
 
-### Tags:
+### Tags
 
 - ZFS stats (`zfs`) will have the following tag:
   - pools - A `::` concatenated list of all ZFS pools on the machine.
@@ -233,9 +233,9 @@ On FreeBSD:
 - Dataset metrics (`zfs_dataset`) will have the following tag:
   - dataset - with the name of the dataset which the metrics are for.
 
-### Example Output:
+### Example Output
 
-```
+```shell
 $ ./telegraf --config telegraf.conf --input-filter zfs --test
 * Plugin: zfs, Collection 1
 > zfs_pool,health=ONLINE,pool=zroot allocated=1578590208i,capacity=2i,dedupratio=1,fragmentation=1i,free=64456531968i,size=66035122176i 1464473103625653908
@@ -287,6 +287,7 @@ A short description for some of the metrics.
 
 `arcstats_evict_l2_ineligible` We evicted something which cannot be stored in the l2.
  Reasons could be:
+
 - We have multiple pools, we evicted something from a pool without an l2 device.
 - The zfs property secondary cache.
 
@@ -313,6 +314,7 @@ A short description for some of the metrics.
 `zfetchstats_stride_hits` Counts the number of cache hits, to items which are in the cache because of the prefetcher (prefetched stride reads)
 
 #### Vdev Cache Stats (FreeBSD only)
+
 note: the vdev cache is deprecated in some ZFS implementations
 
 `vdev_cache_stats_hits` Hits to the vdev (device level) cache.
@@ -320,6 +322,7 @@ note: the vdev cache is deprecated in some ZFS implementations
 `vdev_cache_stats_misses` Misses to the vdev (device level) cache.
 
 #### ABD Stats (Linux Only)
+
 ABD is a linear/scatter dual typed buffer for ARC
 
 `abdstats_linear_cnt` number of linear ABDs which are currently allocated
@@ -343,6 +346,7 @@ ABD is a linear/scatter dual typed buffer for ARC
 `fm_erpt-dropped` counts when an error report cannot be created (eg available memory is too low)
 
 #### ZIL (Linux Only)
+
 note: ZIL measurements are system-wide, neither per-pool nor per-dataset
 
 `zil_commit_count` counts when ZFS transactions are committed to a ZIL