docs: wordsmith fetch & fetchpost description and usage text

[skip ci]

README.md

@@ -44,7 +44,7 @@
 | [explode](/src/cmd/explode.rs#L2)<br>🔣👆 | Explode rows into multiple ones by splitting a column value based on the given separator.  |
 | [extdedup](/src/cmd/extdedup.rs#L2)<br>👆 | Remove duplicate rows from an arbitrarily large CSV/text file using a memory-mapped, [on-disk hash table](https://crates.io/crates/odht). Unlike the `dedup` command, this command does not load the entire file into memory nor does it sort the deduped file. |
 | [extsort](/src/cmd/extsort.rs#L2)<br>🚀📇👆 | Sort an arbitrarily large CSV/text file using a multithreaded [external merge sort](https://en.wikipedia.org/wiki/External_sorting) algorithm. |
-| [fetch](/src/cmd/fetch.rs#L3)<br>✨🧠🌐 | Fetches data from web services for every row using **HTTP Get**. Comes with [HTTP/2](https://http2-explained.haxx.se/en/part1) [adaptive flow control](https://medium.com/coderscorner/http-2-flow-control-77e54f7fd518), [jaq](https://github.com/01mf02/jaq?tab=readme-ov-file#jaq) JSON query language support, dynamic throttling ([RateLimit](https://www.ietf.org/archive/id/draft-ietf-httpapi-ratelimit-headers-06.html)) & caching with available persistent caching using [Redis](https://redis.io/) or a disk-cache. |
+| [fetch](/src/cmd/fetch.rs#L3)<br>✨🧠🌐 | Send/Fetch data to/from web services for every row using **HTTP Get**. Comes with [HTTP/2](https://http2-explained.haxx.se/en/part1) [adaptive flow control](https://medium.com/coderscorner/http-2-flow-control-77e54f7fd518), [jaq](https://github.com/01mf02/jaq?tab=readme-ov-file#jaq) JSON query language support, dynamic throttling ([RateLimit](https://www.ietf.org/archive/id/draft-ietf-httpapi-ratelimit-headers-06.html)) & caching with available persistent caching using [Redis](https://redis.io/) or a disk-cache. |
 | [fetchpost](/src/cmd/fetchpost.rs#L3)<br>✨🧠🌐 | Similar to `fetch`, but uses **HTTP Post** ([HTTP GET vs POST methods](https://www.geeksforgeeks.org/difference-between-http-get-and-post-methods/)). Supports both HTML form (application/x-www-form-urlencoded) and JSON (application/json) content types. |
 | [fill](/src/cmd/fill.rs#L2)<br>👆 | Fill empty values.  |
 | [fixlengths](/src/cmd/fixlengths.rs#L2) | Force a CSV to have same-length records by either padding or truncating them. |

src/cmd/fetch.rs

@@ -1,6 +1,6 @@
 #![allow(unused_assignments)]
 static USAGE: &str = r#"
-Fetches data from web services for every row using HTTP Get.
+Send/Fetch data to/from web services for every row using HTTP Get.
 
 Fetch is integrated with `jaq` (a jq clone) to directly parse out values from an API JSON response.
 (See https://github.com/01mf02/jaq for more info on how to use the jaq JSON Query Language)
@@ -43,8 +43,8 @@ If you don't want responses to be cached at all, use the --no-cache flag.
 NETWORK OPTIONS:
 Fetch recognizes RateLimit and Retry-After headers and dynamically throttles requests
 to be as fast as allowed. The --rate-limit option sets the maximum number of queries per second
-(QPS) to be made. The default is 0, which means to go as fast as possible,
-automatically throttling as required.
+(QPS) to be made. The default is 0, which means to go as fast as possible, automatically
+throttling as required, based on rate-limit and retry-after response headers.
 
 To use a proxy, set the environment variables HTTP_PROXY, HTTPS_PROXY or ALL_PROXY
 (e.g. export HTTPS_PROXY=socks5://127.0.0.1:1086).

src/cmd/fetchpost.rs

@@ -1,6 +1,6 @@
 #![allow(unused_assignments)]
 static USAGE: &str = r#"
-Fetchpost fetches data from web services for every row using HTTP Post.
+Fetchpost sends/fetches data to/from web services for every row using HTTP Post.
 As opposed to fetch, which uses HTTP Get.
 
 CSV data is posted using two methods:
@@ -58,8 +58,8 @@ If you don't want responses to be cached at all, use the --no-cache flag.
 NETWORK OPTIONS:
 Fetchpost recognizes RateLimit and Retry-After headers and dynamically throttles requests
 to be as fast as allowed. The --rate-limit option sets the maximum number of queries per second
-(QPS) to be made. The default is 0, which means to go as fast as possible,
-automatically throttling as required.
+(QPS) to be made. The default is 0, which means to go as fast as possible, automatically
+throttling as required, based on rate-limit and retry-after response headers.
 
 To use a proxy, please set env vars HTTP_PROXY, HTTPS_PROXY or ALL_PROXY
 (e.g. export HTTPS_PROXY=socks5://127.0.0.1:1086).