feat: enable multi page star fetching for private vercel instances (#2159)

* feat: enable multi-page stars' fetching for private vercel instances

This commit enables multi-page stars' support from fetching on private Vercel
instances. This feature can be disabled on the public Vercel instance by adding
the `FETCH_SINGLE_PAGE_STARS=true` as an env variable in the public Vercel
instance. This variable will not be present when people deploy their own Vercel
instance, causing the code to fetch multiple star pages.

* fix: improve stats multi-page fetching behavoir

This commit makes sure that the GraphQL api is only called one time per
100 repositories. The old method added one unnecesairy GraphQL call.

* docs: update documentation

* style: improve code syntax

Co-authored-by: Matteo Pierro <pierromatteo@gmail.com>

* lol happy new year

* docs: remove rate limit documentation for now

Remove the `FETCH_SINGLE_PAGE_STARS` from documentation for now since it
might confuse people.

* fix: fix error in automatic merge

* feat: make sure  env variable is read

Co-authored-by: Matteo Pierro <pierromatteo@gmail.com>
Co-authored-by: Anurag <hazru.anurag@gmail.com>

readme.md

@@ -93,7 +93,7 @@ Visit <https://indiafightscorona.giveindia.org> and make a small donation to hel
     -   [Language Card Exclusive Options](#language-card-exclusive-options)
     -   [Wakatime Card Exclusive Option](#wakatime-card-exclusive-options)
 -   [Deploy Yourself](#deploy-on-your-own-vercel-instance)
-    - [Keep your fork up to date](#keep-your-fork-up-to-date)   
+    -   [Keep your fork up to date](#keep-your-fork-up-to-date)
 
 # GitHub Stats Card
 
@@ -264,7 +264,7 @@ You can customize the appearance of your `Stats Card` or `Repo Card` however you
 -   `border_radius` - Corner rounding on the card. Default: `4.5`.
 
 > **Warning**
-> We use caching to decrease the load on our servers (see https://github.com/anuraghazra/github-readme-stats/issues/1471#issuecomment-1271551425). Our cards have a default cache of 4 hours (14400 seconds). Also, note that the cache is clamped to a minimum of 4 hours and a maximum of 24 hours.
+> We use caching to decrease the load on our servers (see <https://github.com/anuraghazra/github-readme-stats/issues/1471#issuecomment-1271551425>). Our cards have a default cache of 4 hours (14400 seconds). Also, note that the cache is clamped to a minimum of 4 hours and a maximum of 24 hours.
 
 ##### Gradient in bg_color
 
@@ -354,7 +354,7 @@ Use [show_owner](#customization) variable to include the repo's owner username
 The top languages card shows a GitHub user's most frequently used top language.
 
 > **Note**
-> Top Languages does not indicate my skill level or anything like that; it's a GitHub metric to determine which languages have the most code on GitHub. It is a new feature of github-readme-stats._
+> Top Languages does not indicate my skill level or anything like that; it's a GitHub metric to determine which languages have the most code on GitHub. It is a new feature of github-readme-stats.
 
 ### Usage
 
@@ -498,7 +498,7 @@ By default, GitHub does not lay out the cards side by side. To do that, you can
 
 ## Deploy on your own Vercel instance
 
-#### [Check Out Step By Step Video Tutorial By @codeSTACKr](https://youtu.be/n6d4KHSKqGk?t=107)
+#### :film_projector: [Check Out Step By Step Video Tutorial By @codeSTACKr](https://youtu.be/n6d4KHSKqGk?t=107)
 
 > **Warning**
 > If you are on the [hobby (i.e. free)](https://vercel.com/pricing) Vercel plan, please make sure you change the `maxDuration` parameter in the [vercel.json](https://github.com/anuraghazra/github-readme-stats/blob/master/vercel.json) file from `30` to `10` (see [#1416](https://github.com/anuraghazra/github-readme-stats/issues/1416#issuecomment-950275476) for more information).